First off, IPAs are old, so are sours, so are saisons. There really is no new style of beer jumping on the market. The word fad doesn't really apply. They aren't going anywhere either, because they are GOOD. This is why the style is around. I can appreciate nearly every style, so do many people, which is why they have carried on for 100+ years, at least.
Also, most of this is not brewery driven...its driven by the consumer. If you don't like IPAs, dont buy them, but be sure to buy other styles. If the demand is up, breweries will make it. Same goes for the store. They put beer on the shelf that sells. They are a business that needs to succeed.
Finally, it sounds like some people have really crappy bars and beer stores. I suggest finding a nice one that has a lot of variety. Stick with them. My local watering hole is very balanced with nearly every style, about 5-10 beers in each. Even the tap selection varies considerably. My craft beer store is amazing. Whole section for imports of all types, very evenly spread. I'd even say that IPAs are a minority in the store.
And to prove my point about sales driving "fads" the beer manager was screaming at his distributor one day when they said they couldn't get him Mike's Hard Lemonade anymore. This is a nice craft beer store and the distributor looked a little puzzled. The manager explained that one dude buys nearly a case a day of the stuff, let alone anyone else that buys it. He buys what sells.