I don't think it is very courteous to get on a full bus and expect that someone else give you a seat. I think it is pretty discourteous to your own family to put them in that position in the first place.
Someone can't see to it that their family is safe and comfortable, yet a complete stranger lacks common courtesy for not doing it instead? No.
If someone freely offers their seat, then that is great! But getting on a bus expecting someone to do so and then getting mad when they don't is not great. Pretty rude and self centered.
Well said.
The funny thing is that I do generally give up my seat (I have lupus and, if I'm having a bad day, sometimes need to stay seated). However, I find it rude for people to expect that others will get up for them - especially under the guise of "common courtesy" and having been raised better.