My martial arts experience is fairly similar to yours, 10 years ago I'd be in complete agreement with what you've said. My background was in TKD where fast non-telegraphed kicks are the name of the game, when I started in kickboxing & Muay Thai, pretty much everyone's kicks seemed like they were moving in slow motion. They had a hard time hitting me but when they did it hurt like hell, and I had a fairly easy time landing but couldn't hurt them much unless I nailed a step in side kick or spinning back kick.
Fast forward to 10 years ago or so and various folks on Youtube putting up videos of fighters in the Thai stadiums. Long story short, the way they kick was quite different than the way Muay Thai instructors over here were teaching us to kick, the Thai style round kick has a lot of the features of a TMA kick that made it faster and a lot less telegraphed than the version I was being taught. Like a TMA kick, the Thai style kick starts starts straight from the stance without moving the front foot, the kicking leg also comes straight up and then turns over once the right height is reached. The base leg pivots to open up the hips and drive the kick through. It's not quite as fast as the TKD round kick, but it has more weight & power behind it.
Funny enough this was the way I'd taught myself to kick; I hated the out & around "Muay Thai" kick that I was being taught so I kept cheating it back as close as I could to a TKD roundhouse without having the instructors yell at me too much. The balance I arrived at turned out to be pretty close to the Thai style round kick.
