Pete's gift is choosing exactly the right notes and chords for the situation, not blazing fast chops. The one-note solo in "I Can See For Miles" is pretty simple, yes, but it's the way he plays that one note that sells it. There are syncopation and dynamics, and I'm pretty sure he knew exactly what he was doing. It seems to me that the idea was to see if he could play a one-note solo and play the hell out of it. Considering that this was 40 years ago, it's not bad. And again, the point is that it's what is right for the song.
Still, don't sell Pete short on chops. Listen closely to some of his acoustic solos during otherwise electric tunes. "Who Are You" for example. The bridge between "Overture" and "It's a Boy" for another. Those are some smoking solos.
I pretty much agree with you about Roger and Pete calling themselves The Who, when half of what defined The Who is dead. Yes, it's up to them what they want to do with the name, and to many, The Who is about Pete and Roger. But without John's aggressive bass and Keith's thunderous drums, it really doesn't sound anything like what you associate with The Who.
I think Led Zeppelin did it right. When John Bonham died, Robert Plant said that Led Zeppelin was over. They might find another drummer, subsets of them might still play together (and indeed Robert and Jimmy have done a lot), but they would not call it Led Zeppelin, because Led Zeppelin was those four guys, and one of them is gone.