For the record....buses do very well in crashes. Yes, people may be injured but usually not severely. It is everyone's own choice as to whether or not to get on a bus...if they are going to be uncomfortable standing, then they shouldn't board the bus to begin with if there is a large group before them. No, I am not saying that able bodied sitters shouldn't give up their seats if someone in need gets on the bus...of course they should. For crying out loud, I'm 60 and give up my seat all the time. It makes me laugh when some nice young man tries to give me his seat...no, I tell him, I'm fine. Let someone in need have it.
But what I am saying is this.....do not ever depend on the goodness, or good manners, of others in getting a seat. You may very well be on a bus, that is full, but with no one that is willing to give their seat to you. I have an issue with very young kids on the buses anyway...way too many germs in such close quarters but that's just me. I think that if I had kids under the age of 5, I would rent a car, but again, that's just me.
I really don't want to see this turn into bashing of those who don't give up seats. My dh looked very able bodied but with the knee he had before replacement surgery...well, you didn't want him standing on a moving bus!!! Or my idiot father, who with his inner ear issues, would still get up and give you his seat....just because he looks drunk when walking around due to that inner ear issue, doesn't mean he is drunk. But he sure as heck shouldn't be giving up his seat to anyone!!!
We just have no idea who is able and who isn't. Let's just assume that those who don't give up seats, have a valid reason for their actions (or inactions depending on how you look at it).
As for the rude woman in the OP post....I think she was wrong. She could have stood up and given up her seat, rather than hold the stroller. She had no business putting her nose into someone else's business. Forget about it, and her...not worth the effort to give it any more thought.