There isn't only one kind of power user, and not every kind of power user will like KDE. I use GNOME almost daily, with KDE being my primary daily driver. I just really don't see how GNOME could ever said to be great for power users. There are so many ways you can tailer KDE to specific things you may find yourself doing heavily, that would be impossible with GNOME's UI. Being a power user and using GNOME, to me just means you're using the terminal for everything, which is totally valid.

Linus also may not even really be a power user. He says himself that he rarely writes code anymore, and primarily just sends emails and reviews code.