What I mean is, when you're playing in the competitive scene like I am with my friends, it gets boring playing amongst the same characters over and over again. I play for the adrenaline rush and not experiencing the same move sets over and over again. As of last month I've just started working on strats for Project-M doubles, it has come to my attention that most if not all the enemy players are ditto fox. You may say, "Oh, its because fox is a high tier" and while you're right you're not seeing the point though. Its annoying, and predictable. Look at good players like Hbox or Emukiller. They don't have a strong focus on 2-4 people. They can roster anyone if they needed to. And its funny to out predict double fox because what are they going for? A 46% ratio and an up smash.
Tl;dr mains are uncreative and dull.