Personally, I'm fine with pressing the home button. Don't want to cause an accidental opening of home screen with an unintentional tap on the button. Also, if it has to be just a tap, it might cause conflict for some apps that use the fingerprint sensor. (For example, I'm using an app locker with fingerprint lock.)
Actually, touching the button does have a function besides sensing fingerprints, although not as useful. It lights up the capacitive buttons when they're off (probably just detecting a touch).
What I would like, however, is for the long touch/press for Google Now to work.