The reasoning is explained here https://juraj.bednar.io/en/blog-en/2020/11/12/how-could-regu...

In short, if a miner chooses to include banned transactions in its block, it means that block cannot be built off of by fully regulatory compliant miners. Fully compliant miners will be still building off the previous block in the chain. If fully compliant miners win the hash race and mine the next 2 blocks, the original miner's block will not be part of the longest chain, and they will lose all their block reward.