Dude, no offense, but those are some pretty stupid reasons
1: There are people that get over-excited over just about anything. For instance, people who collect toys based on a 1977 sci-fi/fantasy movie and then talk about them on internet message boards
2: The first Harry Potter book came out in 1998. Its now 2003 and its more popular than ever. That's not a trend. New Coke was a trend
3: I'm not sure why earning more money is a bad thing. I am willing to bet that JK Rowling has always envisioned telling the Harry Potter story over a series of books, not just one. By your logic, anyone who wants to make money than is needed for a comfortable life, is a money grubber
4: Of course kids can't be wizards, just like people can't have jedi powers, have working lightsabers, and have spaceships that can travel at faster than light speeds.
Your kung-fu is weak. You're certainly free to hate Harry Potter if you want, but if I had to guess, you're a teenager trying to be a rebel. Right now everyone loves Harry Potter, therefore, its pretty easy to be a rebel by hating it