Hallelujah. The last page of discussion is the most rational discussion I've ever seen on this website regarding WDHs.
Yes, in some situations they are preferred or even necessary to safely pull a trailer, BUT....
Take away the TTs that are poorly balanced/loaded and the lighter duty tow rigs that don't have the suspension or axle capacity and the need for them virtually disappears.
WDHs are about 98% a device solely used with travel trailers, yet TTs only account for a small % of the overall number of similar size trailers pulled every day. That in itself says something.