I know alot of Liverpool fans, from living down here for a long time and they've got alot more in common with us than you'd think. In the Keegan years (early to mid 90s) we were on the rise, playing entertaining and attacking football and had just come up from the first division and were challenging at the top, almost straight away. This was after being in the doldrums for years, so due to riding the crest of a wave, the atmosphere was great for a few years. That atmosphere disappeared under Dalglish and apart from a period of Robson its never really returned.
Liverpool had a great atmopshere at Anfield and on the Kop in the 60s, 70s and 80s when they were top of the pile but their decline under Souness, co-incided with the standing Kop disappearing (which was what made Anfield the atmosphere it was) and the atmosphere has declined over the last few years. They can still raise the roof, in European games and games against United and Everton but week to week it is quiet. I remember the two 4-3 games and the roof nearly came off and I can honestly say, I haven't heard a noise like that at St James' for a long time.
It all depends where you sit as well at a ground. In the away end at Newcastle or Liverpool you can't hear the home fans, unless its a really good atmosphere. The noise from the Kop, won't travel to the away fans, when you've got 3,000 Geordies singing all game and they get sick of hearing the same crap every week from the away fans. Also its easy to say "They should get excited by winning 3-0 and with a good team" and they should do but while we've been in the doldrums for a few years, they're in the same position year after year. They haven't been in a title race since they last won the league 18 years ago but haven't finished outside the top 5 for ages, or outside the top half for donkeys years. That's why their atmosphere is better in Europe and in cups because they know they've got a chance of winning a trophy there. I doubt Anfield would have been silent last week, if they were actually going for the title. Plus the older fans have been there seen it and done it in terms of Liverpool winning trophies so alot of them have got complacent and they suffer more than we do for daytrippers and southern gloryhunters.