You can make fun of the OP all you want, but it is a legit issue in terms of the current implementation. The reliability of the home button is a known defect; if your device is still under warranty, Apple will replace it for free.
As previously Apple has been releasing new iPhones yearly, and the iPhone having a 1-year warranty, that was never an issue. I have had to replace two iPhone 4s because of the home button flaking out. But now that a year is passed, those who didn't buy the extended AppleCare on the phone are left with flaky home buttons and no cheap way to get it fixed.
The home button on my third iPhone 4 is getting very unreliable now (it only works a small percentage of the time). I'm planning on just making out as best I can until iPhone 5 hits, as I can either shuck out $200 to get a new iPhone 4 or hobble along for a few more weeks/months and shuck out $200 for an iPhone 5.
If the OP was talking about the concept of the home button as a user interface element in general....not really sure what to think about it. I haven't had experience with any other smartphone that didn't have something similar, so I don't have a basis for comparison. Interesting to think about, though, given the rumors in the past that Jobs wanted to eliminate the physical home button.