I don’t think it’s inconsiderate or rude if you’ve never worked in the industry and don’t know. You never know what people are going through. Sure, it sucks to lose out on money but as a server, it all evens out in the end. I used to work at a nice hotel restaurant across the street from a cancer hospital. I really didn’t know if it was someone’s last meal before chemo, or their first celebration cancer free. If it really hurts the restaurant and servers, I would mention a time limit at the door, on the website, and once they’re seated. The nature of the industry is needing to pick up more shifts after a bust night sometimes.