I agree that fine motor control would be awesome, but the Valve Index controllers do not measure finger movement with the degree of control that would keep it from frustrating the hell out of people.

The tracking is basically "finger open or closed" and even then it's not terribly accurate. It frequently won't pick up fingers next to each other correctly -- if I point at something with my index finger, it picks out the middle finger as extending as well (even if it didn't). The way they track the thumb movement in particular does not feel remotely natural; it feels like you have to press an awkwardly-placed "close thumb" button rather than just making a fist.

The Valve Index's finger tracking is a gimmick in its current implementation. I really don't think we'll be able to get accurate motor control without a glove.