Doug, the issue with that approach, and many are now using it for sheltered waters or short coastal work, but if one had to abandon ship in some real nasty stuff, the issues of swinging out an upper deck dink and lowering it without mishap and in a shape one could board it could be problematic.
I also question the need for a large heavy dinghy. with correspondingly heavier outboard, when in practice all most folk do is ferry two or three people to shore and back or between other anchored craft. Our 9 footer does all we ever need, and I can power it with a simple air-cooled 4 stroke 2.5hp Honda. Never felt the need for bigger or faster, although I know some do go that way. We explore creeks and rivers with ours no trouble.
Horses for courses I guess. But I have witnessed the skipper of a larger vessel anchored nearby manage to drop and swamp two upper deck mounted dinks, with a powered swing davit, one after another, and in a flat calm anchorage. Now he might well have been a bit of a dummy, but...in rough water...?