So, why do I hate Sasuke?
First of all, I do not think Sasuke in general is weak. He has EMS, a power only a handfull of very powerfull Ninja have achieved so far, this alone makes him 'strong' - in theory that is.
The problem with Sasuke is not his 'strength', but his temper and his childish way of thinking about things. For the moment, he is only a kid who found his fathers gun, nothing else. His character itself is a complete mess: He is always saying Revenge her, Revenge there... but where is his hatred directed to? In fact, the only justified target he has at the moment are the two elders of Konoha, who are the only survivers who knew of and helped to arrange the Uchiha wipeout that put Itachi in this bad situation. But instead of targeting those two only, he is targeting whole Konoha? For what reason? Well I get that he is meant to be the main antagonist and the pendant to Naruto, but to littelery let him turn insane just to give him a reason to turn against Naruto sounds like forced plot to me and wrecks the whole character namely Sasuke that we can see at the moment.
Pre Shippuuden Naruto was a moron, someone who would say childish things and someone who would only get through live, because he had some insane power sleeping inside of him. Sasuke at the other hand was a cool, sharp and almost an mentally adult person. He had his completely understandable goals, a smart way of thinking, a little bit of a cold attitude and a rival. That all made him a very interesting and likeable character.
Now in Shippuuden things turned around completely: Naruto grew up, he learned to get along without depending on the Kyuubi, he is standing up for something and now he even learned how to control the Kyuubi, giving him not only more power, but also the necessary control of that power. Long story made short: he's becoming a man.
Sasuke on the other hand is beeing used, controlled, and has to admit that every time he is somewhat achieving his goal, that he was just a dumbass and that what he was doing didnt make any sense at all. He's getting more reckless, too. In almost every fight he is overdoing it by far. He almost kills himself because he thinks he is the strongest, while beeing completely unable to use his powers to their fullest. While having even better eyes than Itachi, he does not know how to use them correctly, plus he is rushing into every fight without planing beforehand, making him a bad ninja. In fact, it feels like Sasuke grew either mentally younger or insane, depending on how you want to call it.
That's why I hate sasuke. I hope Kishi makes him grow some balls once in a while, he really needs a workover right now. Atm, he is a bad character from my point of view, thats why I hate him. In potential, he is Top 5, if you need to have rankings, but in a real world scenario, he would not make it into the top 10, sadly as it is.
I know Sasuke Fanboys will disagree, but nobody will stop their 'Lord Sasuke' trip anyways, so come at me