Miners who cheat will be punished even more under PoS than under PoW, provided they are caught. If you get caught mining a "bad" block under PoW, you lose only

Miners who cheat will be punished even more under PoS than under PoW, provided they are caught. If you get caught mining a "bad" block under PoW, you lose only the work that went into that block. If you get caught mining a "bad" block under PoS, you lose everything you staked on that block. It's almost as if you have mining hardware that doesn't use any electricity, but self-destructs if you misbehave.