We can whine on about atmosphere and singing as much as we want the fact is every ground in this country is the same and has been since the introduction of all seated stadiums. Maybe Palace with their small ultra section keep up some noise but that is by generally singing that same song over and over.
I wonder if most moaning actually ever go to s game? I was in SS level one 119 yesterday and I thought the atmosphere was great. We have a fair few lads who keep on singing and get the rest going and generally around the ground I thought it was ok. There are also others who go every game and never sing or appear to show any excitement or passion either. They would seriously be better off staying at home and the money they save watching it on the telly.
As for the away fans sounding louder that is often the case everywhere as they are on a day out and usually pissed, like a jolly boys outing.