Buy Everyone Pizza policy
The Buy Everyone Pizza policy is a general rule of thumb and does not strictly relate to pizza.
A general donation such as pizza for everyone that shows up to a Tuesday night event is expected for things like leaving the space in ill shape, leaving a tool in disrepair without using https://knoxmakers.org/oops or telling someone, etc.
For very large events, offenders are expected to at least contribute in some way. No one expects you to buy 100 people pizza because you forgot to vacuum after using wood tools for a few minutes. It's not necessarily relative and some things will obviously just get you kicked out, banned from a tool or workstation, etc., no matter how much pizza you buy.
This is a casual and informal rule. A benefit is the community gets something and the idea of taking care of the place is reinforced. We have to share our quarters and resources, so leaving the space in at least as good a condition as found is always appreciated. So is pizza when a transgression occurs.