Yes i’ve been during their winter, it’s still less friendly compared to other dances. I mean part of it is due to the nature of the dance itself (being stuck with someone for 3-4 songs with no independent movement)
We usually just have 3-song tandas. Speed-tandas (2 songs) have also been popular in some AT scenes. But, if they play the 'authenticity' card, it has to be 4 (and they're usually less friendly).
The age demographic also has an impact together with number of couples. If younger (and solo), I wouldn't choose AT for its social scene, although some do try hard.
However, once in, it's ok. And, I guess that's where you also 'pay forward' socially by being friendly/sociable with someone. It's not just about cabeceo and getting a tanda in some retro game!
I don’t believe in discarding all the traditions of AT. That would only leave it sterile. The traditions that are practical and work include maintaining a well functioning Ronda, leader’s cabaceo when entering the Ronda, practicas, no overtaking (with caveats), to name a few.
Milongas aren't homogenous. I think, over time, some 'traditions', once perhaps considered 'cute', have slipped away to deal with the real, and different, non-BsAs environment.
Some 'traditions' are just respectful courtesy - and, as you say, practical! Yes, some check before entering the ronda; others barge in. Some hold up the ronda; others move when there's space. Some (ah, London! But also some 'festivals' with 'hotshots'!) have no floorcraft. Prácticas? Usually an informal milonga.
The underlying reason - there aren't hordes of young males turning up looking to find the love of their life via a dance, and showing their skills! It's become something else where the old 'rules' get bent to suit.