Yes - he is irresponsible for carrying for self defense a firearm that, per your description, will only function with ammunition that is clearly known to over-penetrate and risk innocent bystander injuries. If he is lucky he won't injure or kill a bystander, if he is not lucky, he could kill a bystander. How would he be justified in his use of hardball if his 230 grain bullet exited the back of the thorax of a perpetrator and killed a 4 year old child that was standing behind the perpetrator? Would he feel responsible because his only gun would not function with hollow points?
No - in this case he is not irresponsible, but he is not being prudent. You should train and get comfortable with the ammunition that you will use in your carry piece. You don't have to do ALL of your training with the more expensive ammo, but at least enough to know how your firearm will function with said.
Step back, take a deep breath and understand that you are using hardball ammo going against the common practice of using expanding bullets for self defense. There are MANY reasons to carry expanding bullets, and if you only have one gun and it won't reliably fire expanding point projectiles you are being irresponsible if you are carrying that piece for self defense.
I teach use of lethal force, and I instruct my class to carry hollow point ammo for self defense, and I lecture on why.
You are free to do what you feel is right.
best
mqqn
Quite frankly, this demonstrates exactly the same type and level of elitist thinking that results in "common sense" gun control laws.
The object of carrying a defensive side arm is survival. If I know that I will be attacked and have to defend myself when I leave my house I would be foolish to leave my house, and especially stupid if all I carried was a handgun. If I am attacked on the street and have to defend myself everything else is a secondary issue; I am not about to stand there and be killed or maimed just because there is some possibility that my ball ammo might go through my attacker and hit something else. When I am trying to stay alive I think the idea of both an entry wound and an exit wound draining my attacker could be a very good thing.
Simply because a certain level of technology might be available, and might be thought more efficacious in some or all circumstances, does not mean that all other technologies should be forgotten (or banned).
Just because a person has only the means to defend his life in one way does not mean he is being irresponsible by doing so.
Fortunately, in the US we have the right to keep and bear arms. Unfortunately, there are those who wish to restrict that right by limiting the type of arms, the types of ammunition, the means of bearing arms, etc. The type of thinking demonstrated in this thread is no different. For many years we have observed as state and local governments banned concealed carry, while simultaneously banning open carry, all the while claiming that these were just "reasonable" limitations in the interests of public safety. Lately we have seen many efforts to limit certain types of arms, magazine capacities, ammunition types, and other things, all presented as "common sense" measures.
What may sound like a reasonable argument for or against something can lead to de facto prohibitions. No one may have a bicycle until everyone has a bicycle sounds very democratic, even utopian. But it can quickly become something else, as every bicycle must be of the same type and no one can use anything else even if that is all they have.