Who says they should, especially when the "enforcing" can be distilled down to plain old bullying and threatening? If I were the game designer, those ones would be the first to go and then maybe the professor.
I think the fundamental reason that they should is that players are the ones playing the game the most, and in my experience, the most active players usually have a more accurate understanding of what's fun and what's fair than the game designers.
I don't condone death threats; bad behavior comes in all flavors.