Er, not exactly a great reason to quit. If you think staff is abusive, you contact the higher ups for that server, the highest rank, being Director. There's also Admin, as well.
As for "idiots pushing you down on death run, as well as griefing happening without mods there to do anything.", you can ping the mods/staff by saying their name in-game, or come to the forums with proof that they did such a thing. Sometimes it's hard to get proof, so if you can't get proof, at least let the staff know.
Don't let things like that get to you. If you start getting irritated and annoyed at a game, it's best to step away from the computer and cool down, think about other things.
If you're still leaving, I'm sorry you have to go. Not every place is best for everyone.