Good point. Moz was hugely popular in The Smiths and again with Viva Hate and again with Arsenal & Vauxhall and again with Quarry & Ringleader and also with Refusal (I think). Not to mention all his other tour success even when not signed to a label (e.g. pre Quarry). Factor in the amount of TV appearances too (e.g. Jools Holland around Southpaw release, Johnny Carson around Kill Uncle and Arsenal etc.).
He can't be on top forever. People are fickle, especially these days. Ed Sheeran is at the top of the pyramid of mediocrity. That says it all really.
Interesting article here on why most people don't want challenging music.
Music for general societal exhaustion