A non-tanguero: "Why did you dance with that guy in jeans?" (Referring to a photo on Facebook)
Me (after having identified the tanguero with a few questions): Why should I not dance with him? Because he‘s wearing jeans? A lot of guys do that!
The non-tanguero: "In my opinion, this shows a severe lack of respect. ... I‘d dance with him in a club or at a party, but not at a ball. Milongas seem to be formal occasions as it can be deducted from the way women dress up? These occasions ask for a certain respect towards the partners and the setting - as does any other form of social environment. Therefore women should not dance with men, who do not show that form of respect towards them and the occasion. By this, women could actually provoke a change in men‘s attitudes."
My intuitive reaction (not having thought about that question in Tango context a lot): "Hey! I chose my partners according to their skills as dancers and out of sympathy. I am quite picky and dance with very few people. If I‘d start to sort out the ones who are not dressed to my liking, I‘d get to dance even less!"
From then on, the discussion took another turn, but some of the thoughts stuck and kept on working.
You‘ll make new friends and meet people, with whom you have already spend many hours at similar events. They have seen you at the start of the Milonga when you‘re all new and shiny and at the end of it, when your make-up is smeared and your clothes sweaty, your feet swollen and your walk unsteady. They have shared your room at the youth hostel and hung out with you at the swimming-pool. They have seen you cheerful and sad and annoyed and enthusiastic. And you‘ve embraced them so many times... These are no formal acquaintances. They are friends or sometimes enemies. Pretty much like the crowd you used to hang out at university. I expect them to behave politely on and off the dancefloor as I would on any other occasion. If they want to dance with me, I will also expect them to keep up an agreeable level of personal hygiene, to have a comfortable embrace, to connect nicely to the music and to not annoy me by pushing me around or by rattling though memorised steps. But I will not expect them to dress up. When my eyes are closed, I will care about how you move and not what you wear. As you all know, I spend a lot of time at Milongas sitting and watching or talking to people. I can make a very educated guess in saying that the majority of dancers at these sort of event will agree to my last words. (If not, please speak up.)
So. It might be worth while getting a shave, having your hair nicely cut and once in a while wearing a tasteful suit. It‘s not outdated, it‘s not cheesy. It shows respect.