$10/month is a perfect price - that was my exact estimate of what I was willing to pay for this service when it becomes non-free.
To everyone expecting Copilot to magically write the code they are thinking about - you are missing the point. There is a learning curve of using this service that allows you to be more efficient in expressing your ideas. It's not about doing all the work for you. It's like auto-complete on the next level.
Licensing concerns - oh come on.. what is the big deal? There are millions of "for (int i ..)" loops out there. Like anyone gives a damn about 5 auto-generate lines being _probably_ copied from somewhere. Moreover, if you used Copilot just a bit you would know that is not how it works.