The laws in NY.
Money.
Feeling like I'll neglect all of them and never get to shoot most of them.
I think that would be about it. Granted, there would be some sort of negative social stigma against someone with over 100 guns, wouldn't there? Probably... That would only work among others who are hardcore collecters, so maybe there are crowds like that in Texas for example. Maybe even Florida, Pennsylvania, but more than anything, more rural areas.
Even still, in my area (upstate NY) I feel like that would still be looked down upon, or at least given weird looks... Not sure, just my .02.