Liverpool lost the league a year ago by a single point. The margin couldn't have been slimmer. I could point to a number of calls that had they gone differently, would have led to Liverpool winning the league. Had Paul Tierney, for example, applied the same standards to Kane's two footed studs up challenge in the Spurs-Pool game at Anfield as he had to the tackle when he sent Robertson off, Liverpool likely win that game and the league.
While I was pissed at the time of the Spurs game, because I thought Tierney's performance was awful, it is simply just lazy, whining nonsense to blame Liverpool's second place finish on refs or Tierney. Every team has calls go against it, and the impact can be meaningful. It's just self-righteous nonsense to say you're thinking of quitting the profession because of referees.
The refs are human and have a very tough job. My own view is that the standard is generally poor but I also think that it's likely always been this way and that the massive growth of the premier league, and all the scrutiny that comes with it, is why we perceive it to be worse than other leagues.