If you go to other sites like audio karma and audio asylum and DIY audio, lot of horn exposure and leadership from the US.
We know you like to ordain winners and losers and talk about your current favorites while poking at products not etched on your scroll of the month. It's easy without commitment And that's all fine and can be good entertainment - it's not a flaw and I'm not attacking you for it.
But asking about why regional differences are what they are is not an attack on people's choices or horns generally - though ideologies can run deep and some inevitably see it that way and become defensive. Maybe it's not always about winners and losers - though on almost all audio forums there are those who feel the need to view their hobby in those terms.
If it helps, consider the question as: why do audiophiles make the choices that they do? In the US certain speaker topologies sell far more than others. I don't know if more horns are sold in the UK/Europe or in Asia than other topologies - nobody answered that question. Are audiophile buyers simply led like bo-peeps by manufacturers? Many of us go through a process of discovery across our audiophile life. Or are manufacturers led by the market of what sells? Personally I doubt I'd buy expensive speakers from a small manufacturer on another continent - maybe others share that. Surely price is a consideration, but that's not a regional preference - it's true everywhere. I asked if space could be a consideration, given that seems to be somewhat of a regional difference. Folsom mentioned cultural aesthetics. Are there other factors that come into play? Why do we see the (admittedly rough) distribution of differences that we do.