While I do see short guys troon out, they are usually asian or halfies.
In terms of white people though, it does seem overwhelmingly to be tall men. Armchair psychology, so feel free to negrate, it might just be because short men tend to struggle more growing up. Tall guys, or more average guys, don't really go through the same struggles. Some don't really struggle at all. Then Covid happens, lockdowns happen, and they just haven't developed the mental fortitude to deal with it. They fall into trans circles through reddit, get told it will make them happy, and then chop off their cocks and remove themselves from the gene pool.
Napoleon wins.
edit: in terms of my own experience, being short and learning to be okay with that is what led to me solidifying my own identity. I would definitely have gotten sucked into the drain and trooned out by now if I hadn't.