Nagorak:

I'm not sure this is a very strong argument.  There are plenty of people who do things they don't believe in for a living.  At the very least we're talking about a sizable minority of people out there.  If the right kind of money is there, people will do the job, whether they personally believe in it or not. 

I doubt if a mutual fund family, like Vanguard, that aims for low costs would offer that type of person what he or she considers to be the right kind of money.  More money is likely to be available at higher cost investment firms.