Because in theory it's actually better then no acceleration. There have been a number of fps esport pros that have even demonstrated this to be true.

The problems are two fold tho, one configuring it correctly is so beyond fucky as to be borderline impossible for your avg user. Two you need more complex configuration options then what standard windows allows for at a minimum you need x and y axis as well as the ability to set at least a threshold point.

But if you do take the time to configure it correctly for your screen size, dpi, mouse area, and mouse dpi as well as get software that allows you enough control over the curve.

It's actually a massive improvement.

Iv personally put that effort in once before and used it for about 8 months. It was a drastic improvement in control.

When I swapped to a new mouse I gave up on it cause it took me like 30 hours to configure it and train with it enough to use it the first time. And doing it every time ANYTHING in my set up changed just wasn't worth it.

Just using raw and training muscle memory is already enough effort. Adding software config on top is just fucked.