As a coach and a first year ref I can honestly say
I appreciate what refs do on the field much more. It is extremely difficult to see everything on the field, especially when 2 people are watching 22 players, plus coaches, benches, fans, etc. Just as a player will not get every pass, shot, tackle, etc. right, neither will a ref get every call right. They do the best that they can, and we should accept their decisions however fallible they might be, and respect their calls. Before you begin to question a ref's call, ask yourself how you would feel if everytime you took a bad shot a ref said: "hey can't you take a better shot than that? Don't you know how to kick the ball without shanking it? etc., etc." Remembering that we are all human helps us realize we can and will make mistakes as players, coaches, and refs. Learning from those mistakes is what matters most.
And forget not the immortal words:
good teams overcome bad calls.