Earlier today, I talked about my views as Harry as a person in the seventh book. This goes somewhere far different than the issues of government, racism, etc. However, it does tie in with the issues revolving around characters such as Dumbledore and Snape. These people have changed Harry, and his perspective on the world. In fact, every character in Harry Potter has affected his outlook on life. Even the tiniest, most irrelevant characters have had something to say that makes Harry think in a different way than before.
This charges full steam ahead in "The Deathly Hallows". His views are being changed. Harry is a 17 year old boy, being pressured to drop everything he has and fight against the dark arts. He is hormonal, young and moody. I can't say I blame him, but something about his characterization in the seventh book makes me cringe. He goes from this sweet, although slightly naive, boy in his Uncle's cupboard to this brooding, angry man. From the very first book, his eyes open to a world that he never knew existed- that he couldn't ever have dreamed of. But at this point in time, the air Harry gives off is so unappealing to me.
It's not even something I can place, exactly. It's just the way J.K. Rowling writes him in general. Everything he says, and the description following seems to have this tight, arrogant feeling to him. It isn't a specific line, but it's the way he treats other characters. Even Lupin, who is his elder and someone he used to respect immensely, is someone he told off in a less than kind fashion. His attitude is growing strongly irritating. He flips out due to information on Dumbledore's past, when all their conversations had been about Harry. As someone in the book club said, there were more important things going on. Fighting the Dark Lord seems to take an infinitely huge priority about a few months of funk Dumbledore went through when he was 17.
In conclusion, there isn't one piece of textual evidence I can use to support this. It's just the general aura you get (or I get) from reading the seventh book. Such as with Romeo, you get that he's sensitive, gentle and naive. With Harry, I get that he's (currently) angry, irritated and arrogant.