It is beyond me why we don't get the same viewport as Maya/Max.
Good question and one I asked too. Maybe Luceric could explain it better.
Thing is though, we can't just copy/paste the code from Max/Maya into Soft so it uses the same viewport, It actually took a while for Maya to do VP2 and the first release was more about performance over quality. Then over the following versions, they've gradually increased the quality. But Maya's VP2 isn't really a day to day working mode...yet, but I'm sure it will be. Same for Soft's HQV, for me this is a v1.0, alot of work has gone into getting it working and now it can only get better.
Ultimately, the work we undertake is influenced by customers. I sat in several meetings with Chinny presenting the roadmaps and ideas of features, gauging the feedback so the teams could prioritise the work.