I can understand your frustration...but saying that housekeepers work 100x harder than waitresses is just a tad insulting to waitresses, honestly. Both jobs are challenging, and you can certainly work hard as a housekeeper or as a waitress. Both deserve tips!

However, although tipping is nice, it isn't required. When I worked in jobs that received tips, I would have the mindset of not expecting tips. That way, when I did get a tip, it was a pleasant surprise and there was no sense of entitlement. It is unrealistic to expect that everyone tip you, and it'll just lead to frustration.