Zombie Pigmen are maniacs

Basically, you hit one zombie pigman, the entire nether is no longer any kind of safe, within minutes you will have hordes of zombie pigmen trying to kill you, I tested going 1,000 blocks away from the first zombie pigmen I ever hit and the zombie pigmen in the next area were still agressive. Basically instead of just the ghasts trying to kill me I have every zombie pigman in existence trying to kill me. I even wiped out all entities with /kill @e and the zombie pigmen that spawned in their place are still agressive.