Sasuke is a gateway favourite character of the worst kind. It's a bad character, a clusterfuck of story and characterization that isn't very well done by any aspect, but which attempts to compensate for its weaknesses by adding in excessive shipping stupidity and DARKNESS. The normal narutard can see this as the shit it is, and may enjoy it, hate it or be indifferent to it, but all the while recognizing that Sasuke, regardless of their opinion, is a plain bad character.
However, these very aspects that try to smear over the shit of its core make it a breeding ground for aspie, unsociable underageb& retards who engage in every kind of stupidity both online and in the real world. Sasuke all trying his hardest to look cool, the jutsus, peculiar, dark clothes, the whole ninja stupidity and everything about Sasuke fuels their escapist fantasies, while the pity-party character backgrounds, emphasis on revenge, and overall preachiness of the character make it fit just right with the mary-sueish drives of your average preteen and his sense of unwarranted self-importance towards the world. Exactly the kind of shit that makes little kiddies and underageb& retards eat this shit right the fuck up.
Sasuke is basically THE character to attract the most hated anime fanbase known to MAL, which is why, regardless of individual opinions, it is the responsibility of every user to troll the fuck out of this character and everyone who likes it, and ensure that no Sasuke threads ever encourage the newfriends to show their faces here.