You win some calls and lose some calls, but at the end of the day you can sleep good at night knowing it's a game played by humans and reffed by humans.
Put it this way.......PI calls are sooooo ticky tack that 1/2 the time the DB does nothing wrong and still gets called for PI. Also, 1/2 the time WR's actually initiate the contact to try to get a PI called. It's like the charge/block call in basketball. I say charge and the Ref calls a block. Way to much leeway in the determination of the call.
PI is a VERY BIG PENALTY in the NFL. The QB just chucks up the ball, totally under throws it, DB and WR bump and flag it thrown. Spot of foul and 45 yds for the offense on a horrible play by QB.
Personally, get rid of PI.......OR.......HC's get 2 challenges a game, PERIOD. That's it.....So it better be an important call for your team because you only get 2.