For the home cook, microwave ovens seem to be used primarily for reheating and defrostring.
I've worked at a number of places that had an employee kitchen equipped with a microwave. I brought in home-cooked meals and used the microwave to reheat. It was great!
Many commercial frozen (and quite good tasting) meals can be purchased at a supermarket. Because the microwave is safe (eg - it turns off automatically) these meals are great for kids or the elderly, because the cooking is self-limiting.
My Mom, who suffered from dementia in her last years (and therefore could not be trusted to use the stove) was able to learn how to use a microwave. She could "cook" nutrious meals in her home; this enabled her to stay in her home and provide meals for herself. The safety factor of the microwave for anyone who cannot be trusted to use a stove should not be underestimted.