Of course I am. Have you ever played soccer? Depending on the circumstances, what is in fact legal contact can often feel like a foul.Are you suggesting that players don't know what is and what isn't a penalty?
By saying that the referee bases his decision on the reaction of the player you are basically saying that penalties will be called based on what the attackers claim, and if they get it wrong then they will be booted from the game. Utterly silly suggestion.
The reason we have referees is so that you have someone impartial to call the game.