Obviously great for heating up leftovers, frozen meals, etc, but it generally gets a bad rap in the culinary world. However, I've noticed more chefs using the microwave when cooking - David Chang is a big fan of them. Many use them to help with prep.
As a home cook, I find that it saves time. I will often pre-cook veggies in microwave before putting them in a pan with oil. This works really well with Brussels sprouts. I've also microwaved a whole head of cauliflower before drizzling it with oil and spices and blasting it in a hot oven to get color on the exterior. Potatoes are also great in the microwave.
Do any of you use the microwave when cooking?
Edit: I forgot to mention one of my favorite uses for the microwave in cooking - for frying shallots and garlic!
https://www.seriouseats.com/fry-garlic-shallots-in-microwave
Great for this. My wife does this all the time.