Did you read the books? Just curious.
Of course I did. Otherwise I wouldn't be calling it garbage writing. I have read every one of the Harry Potter books several times. Its one of my favorite stories. The only thing I hated in the story was Hermione-Ron's love developement. It was never explained why exactly Hermione started loving Ron. The idea that she might like Ron just sort of came out of the blue in the sixth book. We complain about Sakura's reasons for loving Sasuke. Honestly Sakura's crush is better explained than Hermione's.
The other thing I was disappointed was the final battle between Harry and Voldemort. That was so anti-climatic.
Voldemort: I'll kill you Potter! Avada-Kedavra!
Harry: I shall use the powerful spell I like to use in the most important situations. The almighty - Expilliarmus!
Voldemort: Dafaq is happening? 
Harry: Hahahahaaa! Foolish Tom, I'm the master of the elder wand you are using! I beat Draco Malfoy long ago and the elder wand got pissed at him and decided to make me as its master!
Its a bit fickle, isn't it? Its not going to kill its Master! Instead it'll rebound and kill you!
Voldemort: ........

And some people complain about asspulls in Naruto!!!!!!!!! Its the same in most stories.