Is there a more irritating penalty in football than one for roughing the kicker or running into the kicker? If you really think about it, kickers are protected even more than quarterbacks. Any time a player makes contact with a kicker or punter there is almost an automatic reaction on officials' part to give a penalty.
Why? Generally contact takes place when a player is trying to block the kick, barely misses doing so and in the process makes incidental contact with the kicker. It's not as if players go out there head hunting for kickers. They are football players so it's not beyond the realm of imagination that they might get hit sometimes.
I honestly can't remember the last time a player was flagged for roughing the kicker and after watching the replay I saw an unnatural, malicious act. Most every time it is a player trying to make a play and getting there a half second late and at worst hitting a kicker's leg. When a quarterback gets hit a half second after he releases the ball there is usually no flag as long as the hit is clean.
There have been playoff games decided on these calls. In the 2003 NFL playoffs Titans kicker, Joe Nedney missed a 31-yard field goal in overtime, only to get another chance from 5 yards closer after a ridiculous running into the kicker penalty was called on Dewayne Washington. The call was so ludicrous that after the game Nedney joked he might take up acting.
At least quarterbacks don't draw roughing the passer penalties by play acting. I've seen it happen with plenty of kickers and punters that as soon as a player comes even remotely close to them, they collapse on the ground, writhing in pain. Let's get the soccer (apologies to everyone outside of America) out of football.