

Yes, this is one of the more bizarre cultural differences. I have seen people from the UK object strongly to Microwaving water.
Microwaving food definitely affects the way it tastes because it heats unevenly. Cooking foods different ways affects the outer browning, moisture levels, etc.
Heating water in a kettle on the stove, an electric kettle, a sauce pan, or a microwave doesn’t change the water! If you don’t want to seep tea in boiling water, then let it cool slightly first.
Lots of comments on superheating, mostly to the parent comment, but I’ll put a response here.
You can avoid superheating by putting a reasonable time on the microwave based on the amount of water you’re heating. Especially for something you do again and again, you should be able to quickly get experience with this.