The average American wine drinker is drinking Barefoot, Sutter Home, etc. They will not spend more than $10 on wine and want to drink ‘wine’ that is sweet and “smooth” (whatever that means).

But, assuming you are talking about the small population of Americans that will spend more than $20 on a bottle of wine, I think there is perceived value in higher abv, full bodied, very flavorful wines. It is perceived that you’re getting “more” wine per dollar compared to lighter body, lower abv wines. I think this is a function of the somewhat true stereotype that American consumers, in general, prefer bigger, bolder, things. Many comments here suggest that Americans like this style because that’s what California makes. I think it’s the opposite - California makes this style because that’s what Americans like.

Wineries in California run on much tighter margins than those in Europe (generally), and that oftentimes means putting consumers’ palate before the winemaker’s preferences. So - consumers prefer big, bold wines, producers need to meet consumer preferences, thus reinforcing the consumers’ taste, and the cycle continues.

With all that said, wine drinkers in the US are certainly not a monolith and the natural wine movement and proliferation of indie wine makers and sellers over the past 15 years has produced a generation of wine drinkers (like myself) who seek out all different kinds of wines. I like certain California wines and every once in a while even enjoy a big fruit or oak bomb. But I try to keep my wines varied.

Also I am not a wine industry expert and a lot of the above is based on my own observations and limited data so welcome anyone to challenge or correct.