Just my theory..
dunno about aus and in Europe but in America and certainly the UK you get the guys who have their 'local', and some pubs are prone to attracting a 'certain type' of local. So they will go there every day, sit in the same place, ask the same small talk, order the same drink and same flavour crisps every weekend and perhaps once or twice mid week. Everyone knows them and they know everyone (in that pub), it’s their comfort zone. Now if an outsider like you one day stumbles across their pub and has a wonder in - the moment you open that door, all the heads turn and the place goes silent. A tossers pub basically
These kind of characters upon retirement can sometimes end up in tourist areas of los, and I expect they act the same once they find their 'local'. I’ve only experienced it once or twice, but it’s definitely there. 9 times out of 10 the place will be a dive and those that frequent are the only customers. Chances are they've been with the BG's there a few times and probably consider them 'theirs', or at least would like to think so. They go off with customers but the guy might be bitter about it a little.
Just don’t bother with these places. But seen as though you said this was in soi eric, which is all open air. I can't imagine it really happening in any bars there, it’s too open.
I’ve only had dirty looks from guys my own age in phuket, when going out and about with my ex wife. But that’s to be expected, and I don’t care.