Ummm, all your reasons are very personal and subjective in nature. Therefore they will not apply to everybody, hence they might not be detrimental.Reasons not to have a high cap mag in a major caliber:
Maybe I like big butts....... and my pistol grip can be fat too.
Heavier pistols are easier to control, due to less recoil.
If I have some of those long nose-pickin fingers, maybe the reach to the trigger is just right with a fat grip.
The old "spray and pray" argument..... might be valid for the unskilled or untrained.
Personally, I still would not want to be one of eight guys facing a competent .45 operator with 7 rounds in his gun. Do ya feel lucky today?
I don't know, i'd personally feel worse if he had a 13 round magazine, because then he'd have enough ammo to serve everyone, and seconds for 5 of them!