I've had my iPhone 5 for over a year. The button is just as good as when I got it.
Not all iDevices have issues with the Home Button, but it has been an issue for a ton of people on every generation of iPhone/iPad. (Just do a search on this forum for 'Home Button' and you will get pages and pages of people with issues going back 6 years.) A mechanical button WILL fail over time. This is a fact and one reason I believe Apple is moving to what is essentially a capacitive button (a la Android phones).