Just don't bother logging these people. If enough DX stations do this, they'll get the message when they get their cards back marked "Not in Log".
Nope. No they won't. Not likely. I like to think I'm bright enough to listen to what's going on before I jump into the fray. I like to think I'm wise enough to be considerate. I'd never connect the two if I didn't see it in a 6 page topic. I'd get my QSL card some time after the contact and think, "Huh. Weird". After enough of them, I'd start to get the idea of.. "Huh, Weird and aggravating". But I'd most likely not connect those dots.
I think the best you can do is make people aware of the idea of listening first, approaching a QSO like you'd approach a conversation with a stranger and letting people know that macros, while useful, can be EXTREMELY boring and rude if misused.
Interestingly, the same thing happens on voice. I remember sitting in a pile up recently during an event and having some elderly gentleman make his contact and then start asking the station about their radio.. and how do they like it.. and how long have they had it.. and his favorite radio from back in the day.. and what kind of antenna he's using.. and on and on. Meh.. people are people. The upside is that I'd like to think this guy wasn't being rude on purpose. He was just.. obliviously unaware?? Probably wasn't even thinking about the line, much less holding it up. And I'm guessing he wouldn't get his QSL card and think, "Huh.. I must be sending too much junk in my macros that no one cares about at times when it's not conversationally appropriate".
Maybe the software developers could help. The first screen that pops up when you go to edit your macros should say.. "WARNING: Macros are useful but can be over used. This overuse can be boring and rude if not paired with conversational awareness. Please be kind to your fellow hams and use with care."
And the next screen pops up and says, "No.. really! we mean YOU!"
Ultimately, like in everything else, the problem is people