The problem with Sasuke is that Kishi tried to make him a badass anti-hero like Vegeta but he ended up being your typical sullen and emotive teenager. The crucial difference between them,while they could both be called anti-heroes, is that Vegeta is more in the mould of the tough, take-no-shit type, the Wolverine or Solid Snake-esque character that has almost universal appeal. Sasuke, on the other hand, is much more melancholic and dark in a softer, more passive/vulnerable way, which labels him as an "emo" literary sensibilities finds the former palatable while the latter is distasteful for it leaves the impression of mental weakness of that character.