Our microwave failed about 10 years ago. We used it a fair amount during the infant/toddler stage for warming up food quickly (yes we were careful and stirred thoroughly) but when it broke, I saw no point in buying another.
I rarely missed it - only when my tea or coffee grew cold and I would have liked to re-warm it. DD likes microwave popcorn, but I know it's not healthy, so I don't mind being able to limit that snack.
When we moved into this house last summer, there was a microwave already here. It is handy for quickly heating up milk for lattes, but other than that it just takes up a lot of valuable real estate on my counter.
Whether it's unhealthy or not, I just don't seem to need one often. If I want to re-warm most things, I can do it easily on or in the stove/oven. I don't like ready-made microwave meals, I prefer to cook from scratch. I just can't think of anything important I would do with a microwave.