I don't hate him, and try to defend him when people insult his intelligence for no reason. There are a few things which bug me about him, but I don't despise him.
So what is it that people hate about him? Is it his team? 'Cause he has a good reason for starting fresh in each region - he likes to challenge himself and build his skills by starting from the ground up every time, and he knows that his other Pokémon will be well cared for at Orchid-hakase's lab.
The fact that pikachu is obviously his favoured member of it, yes. I was pretty mad at him for leaving bayleef behind after she tried so hard to gain equal treatment next to pikachu, and nearly
killed Oak when she was left behind during the whirl battle. As much as I hate Paul, I have to say he at least gives his pokemon a second chance, instead of just vowing to never use them again while still keeping them in his posession, leaving them to an eternity of doing nothing. Sure, they won't die at Oak's, but it's not like living the rest of your life on some ranch with nothing to do is the best life.
Mind you, I don't think he's an idiot for starting over with weaker pokemon. There's no problem with a challenge, and I don't think there's any problem with him using weaker pokemon instead of the original stronger ones, but I just feel for all the pokemon who were left behind while pikachu wasn't. And that just proved that chikorita was right about pikachu - he is put above her.
Is it his occasional lapses in intelligence? Well, that's one of his endearing qualities, in my opinion. He wants to learn everything about Pokémon training, which implies that he doesn't know it all yet, so naturally he's going to screw up every once in a while.
I have no problem with that. I just feel sorry for him when he does, because I know people will hate him for it. I don't mind the occasional silly moment, because it's better than having a totally sober main character.
Is it because he keeps defeating the Rocket-dan? Geez, they're the villains, and they try to succeed through illegal and unjust means - and they're constantly trying to kidnap Satoshi's best friend. Why shouldn't Satoshi put them in their place?
This is my main problem with him. It's not that he tries to stop them as much as he seems to have this unjust hatred of them. Take a rhyhorn he met in Orange Islands once. That thing would've
killed him if it weren't for togepi, but he still saved him from falling to its doom. Now, look at what he does if Team Rocket tries to get his pokemon. He oblitherates them. This is a group of broke, starving people, one of whom is an orphan, and the other of whom was driven into a life of poverty from a marital arrangement, and a pokemon who's never had a family, and has worked his butt off only to be rejected, and left as a completely useless fighter. Now why is it that a happily wild pokemon gets his sympathy, when a bunch of broke people don't?
Look at the smoochum episode. First, they try to take a wild pokemon. It's
wild, nobody's property. Now, Ash has taken some pokemon out of the wild before, without using a monster ball. That's what they did. So, he attacks them. Doesn't say to use a ball (which he only does sometimes) or anything, he just attacks them. Granted, this was a pokemon's child, but after they
give up on taking the pokemon, what does he do? Attacks them some more. Nope, doesn't apprehend them, or call the police, he just releases the hounds on them when they aren't even a threat. It seems pretty obvious to me that he has an especially passionate hatred towards them, and shows it a lot.
Though that's just when he attacks them at times he didn't have to, but any other time, defeating them probably just niggles at people who happen to like the Rockets (why not? They're some of the funniest characters), and hates to see them humiliated like they are. Or maybe we just want to see another pokemon besides pikachu to deliver the finishing blow. In any case, the results of the rocket battles bother some people.
Mind you, I certainly don't
hate him. I sometimes question his ways, particularly when it comes to his dealing with Team Rocket, or his favouring of pikachu (which is less obviated than it was earlier). Besides that, I don't find too much to hate about him, and I'll take him over Paul any day.