Actually, this is a really interesting question. I've got some theories but I'd be curious to hear what others think. I think part of it is the love affair Americans seem to have with hops/hoppy beers which started about 10-15 years ago and just keeps ramping up every year. In the early microbrew days a brewers standard flagship was generally a Pale Ale and I think brewers and drinkers have just kept pushing the hop needle up and up to the point where Pale Ales are almost what a standard Lager was 20 years ago. None of this answers the real question though which is what is it about hoppy beers that people love?
I agree and I fall into this category as well. I really enjoy a hoppy beer. The other reason I think they've become more popular is because of their alcohol content compared to lagers and such. IPA's are generally higher in alcohol.