If AFKing was okay, there wouldn't be an option to report people for it. If griefing was okay, there wouldn't be an option to report people for it. Two wrongs doesn't make a right, but if you don't start by AFKing, they'd have no reason to push you. Conclusion: if you don't want the effect, don't be the cause. If you choose to continue AFKing, you have no right to complain about being pushed because you willingly put yourself in that position. You DO however, have every right to report them.