Once upon a time as Sam Calagione of http://www.dogfish.com explained in the article on the Boston globe website about extreme beer that styles were pretty stringent and experimentation was not that forthcoming circa 2003 or so.
I would venture to say that Dogfishhead lead by Mr. Calagione was at the forefront of bending the style rules back then. I remember trying hi Raison D’etre sometime in the early 2000’s and not particularly fond of it at the time but I did like the India Brown!
Anyway the Raison had beets and raisins brewed into it and it was very different from most beers in America at the time. Sure Sam Adam’s had a cranberry ale and there was Pete’s Wicked Strawberry blonde which were both seasonal but other than that the brewing community stuck to strict beer style guidelines. Now a days it’s like anything goes and it’s an interesting time to be a beer lover. Check out the article here. http://www.bostonglobe.com/lifestyle/food-dining/2017/01/31/what-extreme-beer-depends-when-you-ask/XO0EoMe8O8nKpjJRyxakzM/story.html