In my experience most crews tend to be good. Sure, there's the occasional "not so great", but that mix of people is normal and happens in all industries. I do think BA make their crews work very hard - the service standard, especially on J short haul, is a lot more elaborate and detailed than on other airlines. To the point where I think it unnecessary.

In my experience, the thanking cabin crew for their hard work tends to happen on flights with a certain crew mindset. Usually starts with boarding without smiles, no banter, followed by mediocre service, and then frequently ends with the hard work thanks being mentioned. Maybe it is an attitude thing - if I think of my work as hard I'll enjoy it less.