I always hear about crappy home buttons but have never - in any iPhone I've owned or my family members have owned (roughly 25-30 phones, not a large sample but still) - experienced any issue with a home button.
Do people push these things hard or something? I personally like the home button - makes it easier to pop the screen on and off when the phone is lying on a desk without having to reach on the side....that said, if they added some functionality I wouldn't be opposed to losing the physical button in favor a capacitive fingerprint reader.
It's a FACT that all iphones before the 5 have plastic/rubber brackets for the homebutton. That in turn makes them loose and less sensitive the more you push it. Every iphone i have had, and everyone I know that has an iphone has had this issue. The 5 has a metal bracket which is MUCH stronger.