If you ride a bicycle you will countersteer naturally, without ever understanding, and possibly without even realizing you're doing it.
One of the biggest breakthroughs in motorcycle racing was discovering the physics and science behind countersteering so you can make practiced and trained choices based on specific knowledge; long before this discovery, everyone was still doing it.
Naturally, the same goes for game design too. The comment "If a game mechanic is fun, let it be fun..?" makes it sound like you're talking about a different topic. You want to be able to intentionally reproduce mechanics that have good game feel, you're not trying to get lucky and you're certainly not removing fun mechanics based on it. The whole point of having a channel to discuss this stuff is literally the reasoning here, putting something into words so you can specifically use it as a tool is worth it's weight in gold.
The #1 thing on my mind when I am adjusting my character's movement properties is always how it feels to the player. Perhaps the disconnection is because you think its about coming up with the idea for a mechanic; it's not, its about making those existing mechanics feel good/satisfying to the player. But sure, coming up with mechanics would be relevant to a game design channel too.