I have to say that I agree with much of that. One of the problems is that some Liverpool fans have been so eager and, to a point, desperate, to shift any blame from Benitez to other factors that it has naturally caused both pundits, as well as fans of other clubs and even many Liverpool fans, themselves, to become suspicious. Some of it has been truly cringe-worthy, and that has rightly spawned many of the threads both on here and elsewhere mocking what became for some a cult of personality (which, by the way, is almost certainly influenced by the other problems at the club).
But re-writing history works both ways. Just as it's not honest to pretend that Benitez is a legend on a par with Shankly and Paisely, or that he could not have done more to improve the team and their standing, despite the number of players (without mentioning money, because that's contested) that came and went in such a short period of time, so too is it equally wrong to claim that he was an unmitigated disaster for Liverpool. As much hilarity as Liverpool often provided for United fans, it would be mendacious to pretend that there weren't points at which many of us genuinely feared that Liverpool were close to challenging our supremacy. Of course, part of the hilarity was caused precisely because of the improvement and then the eventual fall from grace, but it's only fair that we admit to that.
The main problem for Benitez, in my opinion, was that he did some things so well, but only rarely, in truth, that it magnified the failure to such an extent that it was hard to believe that it was the same team and manager in control of both. At times, the brilliance and the incompetence appeared within one week of each other, and for no apparent reason. And apart from the one season where Liverpool genuinely found the momentum to challenge for the league title, much of the rest of his five year spell, in the Premier League, specifically, was defined by poor results and performances against sides that Liverpool should have beaten, regardless of whether they were challenging for the league title. 5th and 7th place finishes for Liverpool in five seasons simply isn't good enough, and any excuses trotted out as reasons for that failure ring hollow, particularly when compared to how impressive Liverpool were either at certain points in each season, and in the Champions League, in general.
But I defy anyone to say that the way in which Liverpool more often than not set-up for European games was anything other than impressive, even if you didn't much appreciate the style (or lack thereof). I used to watch the games in Europe and think to myself that, while the football was hardly buccaneering, the position of each player in the defence and midfield would squeeze the opposition to the point where there were no easy options to anyone in advanced positions. That simply doesn't happen by accident, which is evidenced by the numerous scalps that Liverpool took during his time in charge against much better opposition on paper. And I have no doubt that it is something that our own manager learned from, particularly as our own improvement in Europe, and the change to a similarly pragmatic approach, came off the back of the arrivals of Benitez and Mourinho to this country.
All in all, then, I would suggest that what made Benitez so difficult to understand as a manager was that there was so little consistency to both his own and his teams performances. Awful and turgid defeats in the league, followed by fantastic performances in Europe, and then a genuine title challenge where Liverpool were by some distance better than United in the final part of the season, followed by one of their poorest seasons in living memory. But overall, it would be hard to argue that there wasn't a consistent, if not quite as uniform or spectacular as some would claim, improvement with time.
When you look at some of the candidates who have been linked with the position, I'd personally rather have Benitez in charge of United than many who have been mentioned. And that really highlights the dichotomy that many Liverpool fans have faced, because despite recognizing that Benitez had made numerous and spectacular blunders, when you genuinely assess who is available, it''s not entirely clear that any of them are actually that much more accomplished.