The problem isn't even necessarily that its hard, because it isn't that hard if you know what you're doing.
Its just that what you're doing is like 60 straight hours of grinding with almost nothing interesting between them.
Oh yeah, and if you don't know what you're doing you'll probably end up with a poor team comp. for the end game and since experience doesn't really leak through that means you have to start regrinding your friends for it, its really just a lot more trouble than its worth
(edited by Setsuna_Tamaki)