Cooking chicken in microwave?
While yes it can be done, I wouldn't choose to do it over another technique unless that was my only option or I just needed some chicken cooked quickly for a recipe where it is used in the cooked form and will have a lot of other flavors added (chicken salad).  Remember that a lot of flavor is due to browning and cooking in the microwave eliminates those flavors.  At least with poaching, if the liquid is REALLY well seasoned you'll still impart flavor.

Any cooking technique can lead to tough and dry meat, including poaching where it's being cooked submerged in hot liquid.  Regardless of the technique, if the proteins heat too hot and too quickly they will constrict quickly and squeeze out the juices.  The result will be tough, dry, saw-dusty chicken or other protein.  This is the same thing that happens when scrambled eggs are rubbery...cooked too long over too high of heat.  The proteins act like sponges that are being wrung out.

Personally I think you have much less control over meat cooked in a microwave because the cooking occurs from the inside outward and the residual heat continues to build more intensely than if it was cooked in a saute pan or on a grill.

Is this something that professionals do?  No.  Microwaves in a professional kitchen are mainly used for melting butter, chocolate, reheating things quickly...much the same as I recommend people do at home.  We do not use them for "cooking".  Although I do use it for sweating onions if that's the only thing I'd be dirtying a pan for...put the onions in a bowl with a little butter, cover and nuke for about a minute until tender.