If you wanted to specifically single out all men from a very general group (and contrast it with ladies, who might do the contrary), then you could say so (again, better not to use that if you are saying this to men, or else they might misunderstand it as reffering to them).
In many contexts "tamci panowie" should work better (you might have a specific group in mind, not all of the men at the party, for example). And if you are not in a formal situation yourselves, you might simply use "oni".
That is due to a number of users 'fighting' for the options of 'you all' and 'you guys' as plural you. But you're right, in terms of register it really looks weird, so I deleted those options from this sentence.
Having said that, there is of course an option that the sentence is ironic, there is no context.
The thing with formal, plural 'you' is that there is also the semi-formal option: using panie/panowie/państwo not with 3rd person plural, but with 2nd person plural. Some people deem that incorrect (as it mixed formal and informal words), but it's definitely in usage. If it was "panowie nie pijecie", I think that would strengthen the possibility of the sentence being ironic.
Using the semi-formal option for singular, like "pan pijesz", really looks rather sarcastic.
Note for the learners: I find this answer a bit confusing as a Polish native speaker. 'Dlaczego panowie nie piją' translates literally into 'Why do not the gentlemen drink?' and Duo doesn't accept it for some reason. Suggeted answer is 'Why don't you drink' which does make sense in Polish if you are being polite, but is not really an accurate translation, which is what the exercise asks for.
Well, as another Polish native speaker I'd say that normally 'panowie' without any further description (ci panowie, wysocy panowie etc.) can only be Formal You. I can agree that in this sentence it can be 'the gentlemen' (I am 'a lady', drinking with other ladies, and our husbands = the gentlemen are not drinking). So ok, added such an interpretation.
But I believe that "Why do not the gentlemen drink?" is not the best way to put it in English. Negative questions are a nightmare to me, but this link (https://www.englishgrammar.org/negative-questions/) shows different solutions.
As far as I was told, "why are not you" is pretty unusual and perhaps old-fashioned, but correct. Well, it's definitely not a recommended option, it's just something that can possibly be accepted. It usually isn't.
https://www.duolingo.com/comment/24024902$comment_id=24540343 Here you have a native that claims that such a construction is perfectly natural for them...
Ah, I'm glad that Polish is generally homogenous and such problems occur rather rarely.