No it's not. The referee is just the shortest practical path to enforce a set of rules, which are the real essence of the sport. This is why people play just fine in parks without referees.

Refs are there to enforce the rules; if the same set of rules can be better enforced by other means, referees should be replaced. Subjective referee calls are a plague on the sport, and they are a prime cause for the dismal amount of corruption in it. The sooner we can get rid of them (or at least reduce their role), the better.

Back to the subject, what I meant is that the fact that the ref has power of life and death over a game is a side effect of his role as the enforcer of rules; but we don't define the game of football as "the game where you have a referee", do we? The essence of football is in its rules, not in how they are enforced; otherwise people couldn't play it in parks without refs.

If tomorrow we could have a perfect "refbot" software that can automatically call fouls from TV with better accuracy than human referees, using it wouldn't mean that we are not playing "football" anymore -- the game would be exactly the same, only rules would be enforced without a human ref. (as a sidenote, such a refbot would wipe out a lot of corruption overnight, and I for one would welcome it with open arms -- never again should we see shambolic farces like the 2002 World Cup, Henry's and Maradona's "Hands of God", etc etc).