I think that's fair comment, certainly one shouldn't join BA expecting a crewroom culture (there isn't one..a crewroom that is, although as you know there is a coffee bar of sorts in crew report) - if you crave banter you either have to hope a group of your mates join BA with you, or you may well have to cultivate a peer group outside BA.
BA can feel really anonymous and isolating and it's literally rare to fly with the same guy twice within a year.
That can be the case, and can have it's advantages, but it also can depend on the fleet - I can't speak for shorthaul but certainly on longhaul one consequence of the seniority system can be the same subset of folks going to the same destinations...be that NBO, LOS or SIN.. doing the late JFK...etc etc. Depending on bidding and preferences certainly on Longhaul you can end up flying with the same colleagues several times a year.