I recently moved to Chicago and my God is it beer heaven! You can't go into a bar without finding craft beer and the majority of bar staff know the type of beer and how it tastes etc. Even the run down bars carry craft beers. Saying that, the majority of my friends over here will drink craft beer or shitty Bud Light, it's all just considered beer over here.
Hopefully it will catch on in Ireland soon. The bar culture is much different here though. Bars are the clubs in the US. People will go out for a night out in several different bars as opposed to starting in a bar and ending in a club. The clientele in these bars are also better and during the day you won't find some auld fella your scumbag in the bar, but it'll be busy with "regular" people. Obviously this doesn't hold true to Mulligans, the Porterhouse and Galway Bay chain etc in Ireland which are usually busy at all times.
Anyway, I think it just comes down to ignorance on the part of some people. I think you can see the openness to craft beers through the generations though, I think each generation becomes more open as they hit their twenties. This in a way holds through for Americans. The beer revolution started in the 80's over here and many people have just grown up with it and it's familiar. In Ireland it really only began about 4 or 5 years ago and people are starting to become aware of the availability of beer other than stout or lager. Just my two cents, hopefully he growth continues anyway.