Yeah, it doesn't make much sense. I have a UK version of their Greatest Hits. There are only 10 tracks, but both "Baba O'Reilly" and "The Seeker" are on there. The latter is one of my top five Who tracks, without question.
Other favorites that aren't included on this Greatest Hits comp: "Going Mobile", "Bargain", "Getting In Tune", "The Real Me", "Sea And Sand", "I Am One", etc. And of course, the breakdown on "Naked Eye" is flawless.
But I only listen to the live shows these days. "Tales From The Who 1973", "Charlotte 1971", "MSG 1974", and "Charlton 1974" are just a few that I'd recommend.