Why would they deal with HTC and not just Steam in general.

I have had Vive since day 1. I am never touching anything HTC again. I'm happy enough with the device and technology I have- but the HTC software is horrendous and there's no place for it. I've heard just horror story after horror story of HTC customer service / repair, wanting $200 for a new controller etc.

Vive Pro is a complete joke, in price.

HTC hasn't done anything positive since the release of the original vive.