I think you mean "represents an entire generation that's only interested in reading Harry Potter".
Potter is a gateway drug. Sure, they may only read about Harry at first, but eventually they'll get the urge to read about other wizards. It might start off as an innocent Neil Gaiman book, but eventually they'll be full-blown readers.
Seriously though, Rowlings has surpassed even CS Lewis and RL Stine in terms of getting young people to read. Whether you are a fan or not, I don't get how you can discount the importance she has had on young readers. The Potter books are by no means light reading, and children are challenging themselves to read these books even though they are usually many levels above their grade level reading. It's also great to see a book become such a major attraction. I had the same feeling about Dan Brown, I didn't think he was all that great of a writer, but tons of people were reading the Da Vinci code. Literature needs superstars like this, it helps every genre and every author.