It depends which person is telling the history, though. The bottom line is that the majority of the footballing world outside of Barca fans - the media and journalists - thought we treated Valverde appallingly and that he didn't deserve to be sacked. This is just simply not true in any way, shape or form. The board, for all of their many, terrible faults, treated Valverde with more respect than they have the best player in our history. They gave him chance after chance, standing by him through thick and thin. It's true that they probably did this, in part because he was a yes-man for their dodgy transactions ('Play Paulinho so I can make money in China' 'Yes sir') when a stronger manager would have told them where to stick it, and because of the senior players backing, but the point remains that they kept him on when he should have been sacked.
People outside of Barca don't look at the fact that the squad and our future was being eroded season after season by a selection policy that rewarded seniority over performance, that the performances were unbelievably tedious week in week out, and that Barca didn't play well at all for the most part under Valverde. The entire thing was utterly fraudulent - bloated by Messi carrying the team and Real/Atletico underperforming in the league. They just look at results, because that's really all that matters to the majority of football fans.
It's a sad fact of life, but we sat through it for two and a half years, so at least we know the truth.