Um, because we प्यार his character? He has a lot of depth, emotion, growth, and back story. His faults just make him better, because they make him stronger and he learns from them. He is tragic, confused, unstable, and lost. All that which just make him a और enjoyable character. Because it makes आप want the best for him, आप want him to get better and see right again. His relationships with the other characters are fantastic, and he just adds to their own character. नारूटो is the दिखाना where everyone isn't perfect, they all have fails. But it just makes them better.
People प्यार Sasuke for many MANY reasons. I wish people would stop thinking people प्यार him just for looks. Frankly I प्यार him and I don't find him that attractive.
Why? Well...As for girls, its और of the mother instinct that kicks in..Sasuke's been lonely and broken and hurt for so long, its instinct which makes girls feel like they want to help him..Also, add to that the fact that he's really good-looking, and the dark-mysterious type, it adds up to crush.
As for guys..Hmm...God knows. I'm hoping someone will give me a better answer than, "Because every guy has a gay side to him".
I really don't know... I mean, I could probably understand his popularity in Part 1, because I personally liked him then. But definitely NOT after that! He should've stopped being लोकप्रिय there because he was so unbearable! Ugh.. I hated him at that time too. But hey, what can we really do? :/