Didn't watch much old ECW, did ya?
It's not the same type of crowd. You don't hear dueling chants when it's Batista, Undertaker, or any of the other top faces, only during Cena. That says more about Cena than it does about the crowd.
That's right. You just hear dead silence during a UT and Batista match after they arrive until they signal for the finisher to alert to crowd to properly pop.