Rafa was known for rotating his squad. But this is essential for any top club who compete in a number of tournaments. Rafa was blasted for it but evidence suggests that Fergie, Mourinho and Wenger all rotated their squads just as much Rafa did. In addition, Rafa doesn't rotate his core players i.e. Reina, Agger, Skrtel, Mascherano, Alonso, Gerrard and Torres were hardly removed from the starting XI. Torres was rotated but that was because of his injuries and he needed protecting.
The same people also blast zonal marking when Rafa introduced it. If done correctly, it is very effective which led us to having one of the best defences and with Reina winning the golden gloves roughly 4 times out 6.
The best thing about Benitez is his stubborness. He is a very thick skinned manager and this is imperative when you are managing a big club. He will do things that you might not agree with but there is method in his madness and it usually pays off e.g. playing 2 holding midfielders (Alonso and Mascherano), rotating Torres (he was still carrying an injury but no knew this), zonal marking etc.
If the CFC fans are upset because of Rafa's comments, then I understand their negativity. But bear in mind that he was managing one of your rivals so he was hardly going to be complimentary.
But if CFC fans are upset because they doubt his credentials, then I seriously question your knowledge. He is a fantastic manager who brought some of the best nights to Anfield as well glory and one of your closest league campaigns in the PL. But most importantly, he created a legacy when he overhauled the Academy and we're starting to see the benefits.