That isn't what happens at all though.
Fans don't forgive or forget refs, they remember their names for years and put the fortunes of their teams down to the ref who happens to be referring that match. Players spend the whole match trying to deceive them. Fans abuse them in their thousands. Managers then attack them after the match. Their actions are analysed in the media.
Nobody in that stadium is perfect. The manager makes mistakes in their line-ups, their tactics, their team talks, their transfer strategy, their subs. Players aren't expected to be be perfect. Nobody expects 100% passing accuracy or 100% shot accuracy or 100% tackles completed. So why do we expect refs (as incompetent as they may otherwise be) to be perfect when they have 22 incredibly fit athletes running around a large pitch, trying to win and often attempting to deceive the referee?
Pushing the ref, regardless of whether it is a shove to the floor or a little push like Ronaldo's yesterday, are unacceptable. I don't get why anybody would want to be a top level referee tbh and people will get the referees they deserve (imo anyway).