I'd like to see citations of court cases that support your arguments above.
Clearly, a business DOES NOT have the right to deny service to protected classes (blacks, women, religious groups).
But I'm not familiar with cases where a business DOES NOT have the right to deny service to someone in a non-protected class (didn't shave that day).
Sgt Lumpy
Preface -- sorry for the length, I hope it isn't seen as being obnoxious in any way. I think your point is a very good one and I want to try to answer it as thoroughly as I can and try to explain where I see this balance falling and why.
I agree on a federal level the law as written would only cover protected groups, but in the day to day enforcement of the laws I'd argue it goes far past that.
First, women are a protected group, roughly 50% of people who would potentially come in the doors. All protected minority groups combined is about the same. So in reality if you tell the protected minority they can't come in b/c they didn't shave or whatever they're going to claim it's on the basis of race or gender or a protected class, and you've already lost the case in the real world. Your real world lawyer fees and grief will be so high there is no way a sane owner would have a "no facial hair" rule b/c it's just a matter of time before it blows up.
so just like my externality point above on carry, in this case the protected class law clearly creates a de facto situation that limits business action far beyond the letter of the law.
Second, some religious groups require facial hair. If I had a "no facial hair" rule and an Amish man walked in I'm clearly in trouble to refuse him service on that basis.
The courts would hold, probably correctly in this case, that my rule was specious and had no weight versus the potential discrimination. In fact IMO you could probably have the ACLU come after you even if no one walked in and had an issue b/c the rule on its face is discriminatory to certain faiths.
So even just sticking to "protected groups" the reality is that ANYTHING that could conceivably touch on a protected group is also in play. The ACLU has filed against many a business for rules they think could touch on such a group in some way, which means that in reality there are LOTS of limits.
Second, the definition of protected groups has been expanded by many states and localities, so it's not just federal groups but any in your area, and then you had better keep up with that stuff if you plan on having any wacky "no facial hair" rules.
For example California specifically says you can't discriminate based on "unconventional dress". That's about the most extreme one I have heard, but it's the law there. It's the "Unruh Civil Rights Act" and basically bans "discrimination" for about any reason deemed arbitrary.
So in Cali they can't in fact refuse you, at law, for looking funny.
I admit Cali is the most extreme example, I'm not claiming that would hold in any state court, but I do think it has a broad chilling impact on any business owner anywhere as it's most definitely the wave of the future. What owner wants to be the case law on that?
The point of all that being, as I said, that in reality those laws prevent you from just arbitrarily refusing service to almost anyone. You will have a potential hailstorm of legal problems even if for some reason you wanted to drive off perfectly good customers, so you don't really have that "right" any more. Even the parts that technically are still under your control are so high potential risk at law you don't do it.
However, there are cases, like the gay marriage cake thing, that highlight the situation. In fact I'll take it one further, to the photographer forced to do pictures at a gay wedding when he disapproves of gay marriage.
Personally as a libertarian type I am not particularly pro or con on that issue, but I am very concerned a business owner can be forced to perform personal services as an individual on that basis. This went beyond him not having property rights, he had no PERSONAL rights either.
If We Don?t Have The Right To Refuse Service, Aren?t We All Slaves? | Say Anything
That link references the actual case, there are no doubt better discussions of the case out there, but the idea is clear - not even personal choice is protected for a business, much less property.
There are others of that ilk. Here's one with a florist and same sex wedding. Clearly a hot area:
State Sues Florist Who Refused Service to a Gay Wedding | Slog
What's interesting in that case is that the state itself initiated the suit, having to bring it as a "consumer protection" case technically b/c the private parties nor the HRC had brought the case.
However, even after all that, courts have in fact held that specious reasons to refuse service won't hold up. Here's a legal site that uses the example of a "lazy eye".
Restaurants: Right to Refuse Service | LegalMatch Law Library
here's another legal site that references some odd cases but again points out that courts will look at the rule and determine if it is arbitrary, and IMO be pretty broad about what constitutes "discrimination" or not:
The Right to Refuse Service: Can a Business Refuse Service to Someone Because of Appearance, Odor, or Attire? | LegalZoom
Here's the last one:
Have You Reserved Your Right to Refuse Service? - Free Enterprise
Courts also tend not to favor arbitrary discrimination. In the past, judges have used consumer protection, unfair business practice, and tort laws to punish such practices.
None of this means that you absolutely cannot refuse to serve a customer. It simply means that you need a legitimate business reason to do so.
I think they sum it up far better than I do. You won't find any lawyer telling you the "we reserve the right to refuse service to anyone" sign has any real meaning. You can refuse service for good business cause, like being disruptive or drunk or threatening, etc., but you'd better have a good and legit reason, not an arbitrary one, even outside California.
Again, I'm not necessarily agreeing with that position. I believe strongly in private property rights. My point is that in a world where business property/ownership rights are already constrained beyond any semblance of them really having any left, we are to let it stand that a business can determine rules that through externality impact my safety and 2nd Amendment rights but we wont' let them set rules on something as innocuous as dress and deportment?
IMO the question of whether a business can have a "no guns" policy should be held to the same standard as any other rule, which means whether that rule is arbitrary and capricious or has some basis and justification. If the courts rule it does then fine, but if in some states the courts hold that those signs do NOTHING to improve public safety (and they don't) and in fact may impede it as well as impede the 2nd Amendment rights of customers outside their store, then those signs should come down just like any other sign enforcing some other rule that isn't justified as needed business practice.
Just hold the 2nd Amendment to the same standard as everything else is all I ask. I see no reason to push it on a business owner, but I see no reason it should be a 2nd class citizen next to all the other things required of them.