As much as we all strive for perfection and not nuking - reality is, it's convenient and makes us more compliant.
Dried out looking Sweet Potatos? you are probably overcooking them in the microwave.
Put the sweet potato on a plate, then cover the sweet potato with a bowl deep enough to completely cover the potato. Microwave for 3 minutes (give or take, depending on the size). Remove bowl, flip tater, replace bowl, microwave for another 3 minutes (give or take, depending on the size).
Be careful when removing the bowl after microwaving, it will be full of steam, so make sure you use your oven mitts or towel to protect your hands from burns.
It does take a little more planning, yet cooking one's food is so much safer. Just think of the original Cavemen! They didn't have microwaves!
Poke holes in it, then place it in a bowl or CorningWare with a little water, put the lid or a plate on, and microwave it accordingly. I use this method all the time and it works like a charm. Hope this helps :D