Maybe I do, but I'm not in a metropolis, so travel out to milongas. I'm probably also giving weight to the alternative, non-metropolitan, scene. Usually older (50 might be young!), more couples, fewer young ones. In fact the young ones might start their own milonga with their perception of Argentine culture. Cabeceo/mirada doesn't work well for some. Interesting that even those who are routinely in BsAs note that the environment isn't conducive to cabeceo. You can argue that it's not been taught (we were), but it's not the culture they want to dance - which is a loss for AT.
YMMV! There's also a large, and growing number, who want alternative music, maybe with some fusion dancing. Cabeceo/mirada isn't their culture either as they're used to just being asked, or asking, verbally for a dance. They find the traditional milonga culture much less 'fun'. To an extent I sympathise having recently attended a small but crowded milonga, with minimal formal cabeceo, which was certainly great fun with good traditional music, and a larger, but more traditional Argentine culture, milonga which was much less so (and, somehow, the music wasn't as good either). Noted some ladies leaving early because not being invited (I can only do so much! The TDJ also played his part). Some were looking forward to a regular alternative milonga where cabeceo/mirada certainly isn't used.
A few, or even just one, invites to dance do not comprise their idea of a good evening! Sure, some see it as the norm at a milonga. And, as noted, there's an ocean of mediocre.
I accept that some find cabeceo/mirada works for them, in their situation, with their focus on AT, and in the environment where they attend milongas, but for others, elsewhere, it doesn't - so they sensibly use alternatives.