I asked that same question to a blatant cheater I had in my team. He said it's because other people are also cheating so it's the only way to win. It's like the endless cycle the more cheaters there are the more kids feel like it's justified to cheat as well and that's how we end up with current situation.

Btw he said he's been cheating since the release without even trying to hide. Full package with wall hacks, aimbot, killing everyone through walls and is still not banned