What I have observed with other threads that you have been in also is that you tend to love to disagree with anything that is basic common sense, and you are most of the time unwilling to take advice from more experienced people. I am not saying you are a bad person just that sometimes you act childish just like everyone does (I did so here).
In all seriousness I apologize for getting on your case, I was acting very childish and kind of went after you for other reason that I won't mention. I will be just ignoring your posts from now on so that I don't go after you again.
It's illegal because the mod authors set up the distribution polices for their mods in such a way hat you are not allowed to distribute them without permission, and then the tekkit people asked for permission, were specifically denied permission, and went through with it anyway.
Tekkit/Technic is a bad word in the modding community.