My point is that you have to apply heat for the same amount of time (if not longer due to the lower temperatures that can be achieved by a microwave), so why waste your time with the microwave in the first place? It's probably going to end up taking just as long and using more energy, and the lack of the high temperatures on the outside or any radiative heating means that you aren't going to get any tasty browning. (Plus my anecdotal rubberiness factor.)

On the other hand, there have been times in history when browned meat was found to be gauche, which is the history behind wrapping a filet in bacon; originally it would have been some other cheap meat wrapped around the entire tenderloin roast and discarded (to the servants, most likely) before serving.

There are other concerns, too, like the fact that it's hard to control heating in a microwave, since it there is only one power (that can be cycled on and off on lower power settings on your micorwave oven) and the heat generated depends largely on the specific interactions with the material in the oven.