I think resistance training is one of many good forms of exercise. I can’t say I care deeply if you do it or don’t, but am curious as to the many good reasons one may have stopped doing it or the experiences some folks had.
One of the bad things about exercise is, like diet, the tendency to become dogmatic, like you say. The Crossfitters I know are not too bad, but they have that reputation too.
When I started lifting weights, and it’s been years since I had a very physical job, it was not that popular and gyms were often empty. It has become more popular, but in most gyms I’ve been to you just don’t see many senior citizens doing it. And they are actually the ones with the most to gain from it. Most who did do it seem to stop in their 20s, with many exceptions I’m sure.