He's not an excellent manager and hasn't been for some time.
I'm now imagining your hypothetical scenario where half of the crowd don't react as I suspect. In that scenario, the other half, about 18,000 people will be booing, shouting, leaving early, not turning up at all, basically making their displeasure known if there is a bad run of form, poor play, defensive tactics or just because it's Benitez on the touchline. Toxic. No upside.
P.S. He relegated Newcastle, they were one point from safety when he took over, he didn't even get a dead cat bounce.