I didn't like at first due to the same reason you state. But after a couple of days I saw the benefit of it. It allows you turn the screen on without using the on/off button. It's easier to press and access than the on/off button and saves the wear and tear on it. If you have a case like the Otter Defender, the on/off button is very difficult to press.
I also use a "Screen Off" widget so I can turn the screen off by pressing the widget so, again, I don't have to use the on/off button. The only time I press the on/off button is to turn the phone on if it has been shut off. I reboot/turn phone off with QuickBoot (must be rooted).
I see it as a nice feature now and can see the benefits of the home button. Of course, everyone has a different idea on what is good/bad on a phone.