This also happens with experienced followers, that I have to say: don't press against my arm, please don't press on my shoulder, please dance on your own axis. Most of them apologize immediately and stop bad habits. Of course there are also some who say, oh sorry, most leaders expect it.
This seems to be a gray area where athletic and technical traits might be difficult to tell apart.
I share weight for real – I don't just affect the illusion of doing so. My usual dance posture has my partner and me on one shared axis, close up top and apart down below. The majority of my lead passes through my torso, and functions because the torso and both arms move as a single piece or frame. I do not give arm impulses separate from torso movement, and "volcada" is less a specific movement than the default state for
all movements.
To dance like that, I need my partner to share an axis with me and have a frame like mine. This means they must direct the force of their weight horizontally toward me, and have tonus and presence in their arm on the open side. If we both do this, we have what in the world of aircraft is called "controlled instability": We teeter on the edge of falling (volcada) at all times, and the slightest inflection (lead) creates results almost instantly, which can be very fast and very large if desired.
Lots of tangueras trained in the same broad style as me by the same gang of teachers as mine who had the same group of masters dance this way. I'd say it's "usual" among tangueras in my age group in my city. I don't have to ask for it or "teach" it, because it's a baseline approach . . . I'd only have to speak up if I
didn't want it.
However, there are also tangueras who have poor athletic qualities – bad balance, limited flexibility (especially at the upper body-lower body hinge), weak abdominal muscles, excessive or inadequate control over muscles in their arms and back, etc. – who collapse against me, or direct their weight vertically (downward) onto me, or actively push with the arm on the open side. That's uncomfortable, even for me.
I can immediately tell the difference between these things because one is how I like to dance while the other is not. But if you prefer not to share weight, and to dance on separate axes, then I can totally see how either could be disagreeable to you! Someone dancing my way vs. someone with poor athleticism are
still completely different things physically, but would possibly feel the same way to you.
I guess the solution would be to watch people in a new place to determine what the standard style is there, and to pick the ones who dance like you do. As someone who just about never travels to dance, I'm fortunate in being able to invite most people I've seen around for about as long as I've been dancing, who number in the dozens and possibly the hundreds here.