Like all other airlines, crews can be hit or miss. It can be annoying, I grant you that, and they can also be sub-par... but I think QR crews are usually good and above.
Some of it is a cultural thing in terms of service standards, and it plays into what you expect VS what you get. So when you talk about crews being proactive - QR crews are generally not proactive, but they respond very well to specific requests. Don't wait / expect - use the call button. On US-based airlines, most crew members HATE the call button, but they are proactive. So just a different on-board service culture. I don't think there's a right or wrong - just different.
When I'm lucky enough to fly QR in J, I tell them at the beginning of the flight what I want when, and I use the call button throughout the flight. I end up happy.
I am not fussed about the smiling thing... on a long(er) flight I don't expect crew to be all smiling some 5-10-12 hours into it. Decent, polite service is all I ask. I see that you were really bothered by that... horses for courses.
Dirty dishes left for a long time is something that does annoy me. I'm 100% with you on that one. I haven't had that happen on QR; I suspect that might be an exception rather than the norm. But yeah, annoying