I have watched my sons play soccer for 18 years and more than a thousand games and I can only think of two or three times that I thought a ref's call was the ultimate difference in the outcome.
What has upset me most though is when refs allow aggressive play to go on uncalled, regardless which team is doing it. I think that refs primary mission should be to protect the players. Uncalled aggressive play draws more ire and venom from the players, parents , and fans than any other decision the ref makes. Heaven forbid that a player gets injured as a result of letting aggressive play go unchecked. If that happens then control of the match is in jeopardy and the ref, in my opinion, then deserves whatever language comes his way. A called or uncalled hand ball, offsides call, bad throw-in, etc. is tolerable and its understandable that the ref may make a mistake but its unacceptable to allow obvious and continued agressive play to go unchecked. Even if a take down does not technically meet the qualifications for a foul the ref should warn players or issue cards for dangerous play.