I agree...the plague of YA books that's followed has maybe tainted the view of it for some, but when it first came out, Harry Potter was one of the more talked about books in a long time, and with good reason, I definitely think it has staying power.
That being said...I again hope this YA phase will pass, especially for adults--
It's one thing if you're read such novels as a teen and want to revisit them as an adult, a la Harry Potter...
But I do get a bit annoyed at adults seeking out YA books for a start, rather than looking to either "legitimate" fiction--and I blame the rise of YA novels for that partially being obscured now...even with TV and the Internet, books still remain popular enough to be read, but YA takes the spotlight away from people trying new things or writing "important" works in favor of people just following a now-established formula for paranormal, fantasy, or dystopian romances (some deviate, but they're the exception)--or adult fantasy.
I wouldn't be so snobbish as to suggest fantasy itself is crap...
But reading Tolkien, Martin or even Rowling is different than reading those trying to be a YA version of the first two or a carbon copy of the third.