Through a chance meeting with a mysterious girl named C.C., Lelouch gains his Geass, the power of the king. Now endowed with absolute dominance over any person, Lelouch may finally realize his goal of bringing down Britannia from within!
In my opinion? The fact that it's marketed towards young people that probably haven't been exposed to anything of quality yet, so they grow a fondness for it that would otherwise not be there, had they been older and more mature.
That and Naruto fanboys are the worst fanboys since the Sonic ones, they are the same kind of people who think Linkin Park is good.
Hope you based your opinion on the anime itself rather than the fanboys.
It's derived from the manga and the latter I think is supposed to target young male audiences...
I guess it's difficult for me to claim objectivity on the matter, but the product quality is quite high on this one- higher than most animes at any rate. The level of detail in combats and the uniqueness of the soundtracks play a big role in that.
I can only assume people will not like it if they don't like the characters in there or the story because the animation and music are remarkably good.
I happen to like both Naruto and Linkin Park though, so maybe you've found something of a link between the two.