The situation with Yes is a lot more complicated than most people realize. The band waited years for Jon Anderson to be "ready" to tour, but he was busy with his solo and side projects. Then he got sick. But not so sick that he couldn't go do another solo tour. Somewhere in there, Jon sold his stake in the band, saying it was done, and Rick Wakeman never bought in, which is why he left and came back pretty much whenever he wanted to (three times, maybe four, depending on how you count them). Then when he supposedly was "ready" to join them, he really did get sick. You wait five or six years, you figure maybe it's time to find a replacement, so that's what they did. And Wakeman didn't want to come back if Anderson wasn't there.
And that's just the very short version. Howe, Squire, and White own the Yes name, and while that doesn't mean that they can simply call the shots, I think it's important to note that Anderson sold his share back to them and publicly declared that the band was done in an interview. So was he given the boot, or did he quit?