The beer may have been better over there 30 years ago, but there's no way that's true now. In most places in the US you can't swing a dead cat without hitting half a dozen craft brewers making outstanding beer. You literally can't sample what's available in liquor stores fast enough and a lot of it is really good.
I don't know if this is a trend that has been embraced by Ireland or not, but I would imagine that in many Irish brands suffer from what many "traditional" European beer brands are no different than most American beer brands -- owned by conglomerates, brewed on industrial scales. Maybe it makes you feel more exclusive to drink Harp over Buweiser, but I'm pretty sure its moslty psychological.