Yeah, I did some cursory research and the reason most claimed is that minivans are simply not that popular.

But neither are Hummers, yes they appeal to some people but you really don't see a lot of them out on the road.

Minivans are extremely popular in the US, when lifted and with the roof removed from the back.

I wouldn't call it mini though.

The hauling capacity is equivalent to a minivan, even if the footprint is bigger.