First, comparing across years is tricky because guns and calibration may differ. Are they measuring from release point or some point beyond that? What point beyond that?
Second, it is one thing to be able to throw hard and quite another to be able to throw hard with technique and accuracy. One of the reasons actually watching IS important is to be able to tell who can and can't do which. There is one technique associated with winding up and chucking it as hard as you possibly can and another in being able to apply the right footwork and technique and deliver the ball both on time and accurately with the necessary velocity.
There is certainly a minimal level of arm strength necessary to play QB in the NFL, but once above that and looking at the history since 2008, there is virtually no correlation between success in the NFL and velocity.
