This is a perfect example of the "Rock, Paper, Scissors" debate about PvP. It starts with a strength and a weakness...
Let's use Masterminds as an example.
They have fair damage, good defenses, and even respectable buffs and heals. But one TP-foe and they are as good as dead. But now let's take a look at the TP-Foe'er...
Let's say it's one of those nasty TP-Blasters. He got TP-Foe just for this sort of thing and he's having the time of his life! But he doesn't see the Stalker behind him...
What about the Stalker? If he gets anywhere near the MM without good defense, one of those AoE's is going to knock him out of hide, and he, is a dead stalker near a MM when he isn't hidden.
Sure, there are ways to counter some tactics, but all of them at once?
The fact of the matter is you will beat some people and some people will beat you, even if it's indirectly. I haven't met anyone who can beat everyone, and if you boast a perfect record, then I suspect you've run away or avoided a fight more than once.