You can not copyright an idea, it's a thought, thoughts are free and it's good like that. As you can see from the comments, your idea wasn't even very original, since several others came up with something very similar, without even knowing you.
The most funny thing is that you even complain about them using the same addons - as if there are so many different ones out there. I bet 90% of the people are using the very mainstream versions of specific addon categories. Like Pitbull for unitframes, that awe-full SexyMap thing for the map, Recount, Omen and so on ...
People are overreacting on UIs since the beginning of time. Though, that doesn't make it any more of a good thing/reasonable. This is not about money or anything similar, it's also far from copy/pasting code and claiming it as your own. It's just some kind of layout that can be adapted, or just plain "re-invented" without even knowing it ...
Just stop this misbehaviour, please. There are other, reasonable things to freak out on.
