Bleach isn't unquality because it's popular. It's unquality because it's retarded. It's the author randomly throwing shit together in an attempt to get to the next fight scene. Half of it doesn't make any sense. He kills off Aizen, decides he likes Aizen too much, brings him back and makes him into a supervillain, then kills off Renji and Hitsugaya, then brings them back (lolmagichealing), then Ichigo has a completely pointless fight with Byakuya because Kubo Tite thought it would be cool.
Lots of random fighting with no one dying =/= plot =/= quality... although it does equal QUALITY.
Oh yeah, and spoilers.