The wine industry always was that way. It really took off in America in the 70s and the number of small craft producers has been on an upward slope ever since. While the beer industry consolidated into a small number of large producers, wine has done the opposite.
There are trends (just as everyone in beer spent 15 years trying to make hoppier, higher ABV IPAs) but if anything beer is following wine, not the reverse.
On the other hand, one could argue that the addition of American producers and American consumers has made wine significantly worse over the years as well. Robert Parker has been America’s worst wine export in the past few decades.
One could argue that but I wont. I recall what wine looked like in the UK 30 odd years ago. Nowadays we have an embarrassment of choice including some pretty decent wines from the US.
Just having a large number of small producers does not imply that the market has the amount of product differentiation GP is asking for. Wine I see on shelf does not make much attempt to distinguish itself stylistically from the other products sitting next to it. Going the other way, having a small number of producers does not imply product uniformity. A single brewing company is perfectly capable of making a wide variety of beers.
There are trends (just as everyone in beer spent 15 years trying to make hoppier, higher ABV IPAs) but if anything beer is following wine, not the reverse.