I'll never use a microwave again but that's just me. I'm in search of the highest health possible. They cook at too high a temperature and destroy too many nutrients. They also alter the structure of food and make it nearly unrecognizable by the body.
Microwave some water, let it cool down, water your plants with it and watch what happens.
I don't trust them at all. Some countries have even banned them? They are dangerous in my mind. It's up to you to research it more and believe what you want.