A not-for-profit can charge for service, and cannot return a profit to investors. Maybe they've ways to wiggle around the latter, but not charging for the service is simply irrelevant.
Oh, and they had fire dancers, an open bar, and taxi reimbursement.
10/10 would Christmas party again.
Compensation of employees of a not-for-profit is certainly allowed - that's a different thing than returning profit to shareholders except when it isn't (in which case, IIUC, it comes with restrictions, which isn't to say it's never abused, which isn't to say it's never/always prosecuted, etc, etc...).
I explicitly admitted the possibility of wiggle room around the restrictions - my point was about what the restrictions referred to in the first place.