Sure, one can argue that there are better, deeper, more well-written children's books out there. I would agree, actually.
That doesn't mean HP isn't good. It's top notch, among the best. And to think: I didn't used to like it! That was when only the first three books had been published, and I had not read any of them, but I wasn't impressed with all the hype and huffle about it, so I didn't try. Good thing I got over that.
But really, there is nothing like reading through the entire Harry Potter series in the summer - the fact that they were all released in the summer probably influenced this opinion. Looking forward to a new adventure every other year? Yeah! This has been my summer tradition for the past five years and it's awesome. It's what summer is all about - barbecues, road trips, enjoying large bodies of water, and reading Harry Potter until my eyes are fried.