My friend, who once worked in a classy restaurant in Miami, nearly fell off his chair. So, things are, sloooowly, changing.
That's amazing really, five star service - the hotel by the Orthodox Cathedral is pretty friendly too.
I don't think that laughing to yourself when the service is bad is going to change anything.
More a coping strategy when you get it day in day out. If it makes the person reflect, all the better. I'd stress though that it's an issue - for newcomers and visitors bad service can seem really hostile.
The old women are usually the worst ones
Indeed, though the young aren't always much better - most waiters/waitresses in Warsaw are students rather than professionals and it does show. Last year I asked (a young waitress) if the chips are real or frozen only to be told that as far as she's concerned the whole point of chips is that they're frozen!
I agree though, service in shops is getting friendlier than it used to be and old ladies are the worst. I still very occasionally (much less often than a few years ago) leave stuff on the counter, walk out and go somewhere else if I'm not in a hurry and they start being rude. It isn't as if there's little no competition as in PRL days.
As for other unfriendliness, the only real problems I've had in two decades are drunks and (usually elderly) nutters. I long ago figured that the public transport thing isn't rudeness aimed at me because I look and sound different, it's just the way things are.