Your missing the point. People that bought the Shield instead of the Compact didn't care about the stuff you listed in the first place or they wouldn't have bought Shield, they would have bought a Compact. There are after-market options for the Shield grips, plus, there are also lasers and lights available for the Shield, as well as sights, trigger kits, etc... As far as bullet capacity, well, the Compact is supposed to have a higher bullet capacity...it's a double stack -vs- the Shield single stack. That's not a negative or a positive, both guns were purposely made that way. Once again, one of the main reasons why people that buy the Shield, choose it.
The things you listed as "so much more" with the Compact are, in many case, the actual things the motivated people to buy the Shield instaed of the Compact in the first place. And, as you see, there is already a thread full of people here that completely disagree with your assessment of the "negligible" differences. Both guns are nice, and as I stated (and many others), it comes down to preference. If you like Compact, get it...if you like the Shield, get it. Or better yet, if you can afford both...