The mount system is window-dressing and is completely worthless without the ability to have BOTH a horse and a thrall in your party at the same time. Further, it is worthless without the ability to truss a thrall and sling them over the back of the horse, or drag them behind your horse.
Yes, it is fun to ride around and lance elephants and run down NPCs. But doing that for lulz is not sustainable. To prosecute the core game mechanics, you have to leave the mounts behind, and run everywhere just like before. And now running is about as pleasant as sticking a needle in your eye with this momentum “feature.”
People didn’t want mounts for lulz. They wanted mounts for immersion and convenience. Now we have a half-baked version of mounts that is useless for the most important things in the game at the expense of breaking movement and mobility. I’m not sure anybody wanted this.