I used a tea ball for awhile until it became a pain to constantly get the leftover tea leaves out of all the little divots after every use. The device you posted basically looks like a giant tea ball. I need a single mug fast with minimal cleanup before I leave the house, and tea bags are as easy as it gets. If there's some device that makes using loose leaf tea easier, faster and less messy, then I'm all ears.
The little mug infuser thing pictured up-thread is actually really easy to clean. I just whack it against the side of the compost bin under the sink, and then rinsing any remaining leaves out takes a few seconds.
Also, what's the outrageous difference between boiling water in a kettle or bringing it to a boil in the microwave to the point that someone called it disgusting? You're applying heat to the water and getting the same result; it's just quite a bit more convenient to use the microwave.
Heat water however you like; if you’re using tea bags you’re getting mediocre tasting tea no matter how you heat the water.
Do note that you don’t actually get precisely the same result. For one thing, it’s really hard to get water to be consistently heated to the temperature you want in a microwave (which heats quite unevenly and will also happily heat some of the water beyond the boiling point), whereas if you boil water in a kettle it’s basically guaranteed to all be at the boiling point. There’s also various stuff dissolved in the water (oxygen, carbon dioxide, etc.) that will be released the longer water stays near boiling. I don’t personally find this makes any obvious difference, but some tea connoisseurs claim they get a different tasting result if they immediately use water that has just barely gotten to a boil (in a kettle of course).
If you want to be sure, I guess you could do a double-blind taste test. I’d recommend starting with some good tea though, that’s going to make a much more dramatic difference than using a kettle instead of a microwave.
[Also note, most black tea should be steeped in boiling or near-boiling water; most other types of tea need to be steeped at lower temperatures.]