I think a lot of the hate people have just comes from them not being able to get used to what's called the "trendy" drama style - basically the super mainstream. There's a very different sort of acting that goes in these shows than in something a bit more polished. I wouldn't necessarily call it bad acting, they're just going for different things. It also brings up another hurdle you need to surpass, getting used to Japanese acting in general because the sensibilities are always going to be pretty different from your typical Western show.
I like a lot of the anime/manga to drama adaptations I've seen, mostly the TV shows though. (Cat Street and Honey and Clover are my favorites) Movies aren't that great for adapting a long running story. But I've liked Japanese TV shows beyond anime for quite a while, so I'm used to a lot of those differences that strike people as odd on first experiences. (the at times comical amount of yelling and not facing someone as you talk to them is something that bugs newcomers a lot)
Was totally not a fan of the Battle Royale movie though. I had the same experience with that as I did with The Golden Compass - both movies felt like condensed versions of the story rather than a faithful adaptation.