Impre, the problem of having alts is not about it is better to have alts... The problem is, that some people are lazy to cooperate with others and rather make lot of alts to have a POWWWWEEEER build...
I am playing only one character for my whole game experience and have fun even without alts... in fact I think I have more fun, because I meet with people, make friends, make enemies, trade with people, and so on... and I dont need any imaginary friends (alts), who will craft me tons of armors, weapons, ammo and drugs...