I don't want sharing feature. I honestly think $15 a month for personal use is expensive.
It's such a good tool, but it's hard to reach. I wonder if you could consider a more personal plan. For example, six dollars a month…
I need only the Infinity boards feature with Free plan.
Thanks for your feedback@Atsushi ! 
At the moment Miro is betting on teams as a target audience of our tool, and we focus on team-based plans. We’ll make sure to keep you posted if we decide to create a solution for personal use or teams under five. Stay tuned!
There are various tools with comparable skills. Many users do not need the team functions or only later when their project grows. With a cheap solution for single users, Miro could reach many interested parties. In addition, every satisfied user is a catalyst.