You may very well be correct that it could be possible to make very good wine from other fruit but there's cultural stigma attached and the process isn't as well developed.

In my country it's cold enough for grapes to not really grow well and there are some tiny farms that make and sell fruit wine and they suffer from exactly what you describe - it's very expensive and not well refined.

If you go to one of these places and have a nice experience tasting then you may even come away thinking that it was surprisingly good, but then you take a bottle home and it just tastes like fruit juice compared to good grape based wines...