I think that it's a reasonable license for them to protect their business while continuing to provide full access to the community. The single user would still be able to modify or even build their own clone, but a private company would not be able to just sell a copy.
In an ideal world where money did not exist this would be detrimental to innovation, but in the real world Prusa needs to make money to stay in business. And considering their competitors, I would much prefer them to stay in the business and as much ahead of the competition as possible.
My friend, you are technically correct.
Which is the best kind of correct.