He went into an unwinnable position, on the off chance he might be able to turn things around enough quickly to do well. The fans were more vociferous about wanting him out than they are normally about supporting their own team. He had a go at them for being cunts after finding out he was not coming back next year, saying that he's fucking off anyway, so save your cunt breath. It's not some weird melt down, and it was mostly directed at the supporters, and not the owners. Yea, he knew what he was getting into, but he also knew he'd have this excuse waiting for him, and it's not like it's not a valid excuse. It was part of the risk benefit analysis.
The good thing is that it's given everyone one here, including myself, an opportunity to say where we all are regarding Benitez. Because we didn't already know where we all stood after the last many years.