What was the loss for the company if KSP failed?
They were sponsoring the cost of KSP dev time to keep their lead developer not to actually create KSP. Under your mercenary evaluation of this the company didn't actually have any chance of failure as the dev stays, so by your reasoning the company shouldn't get any of the profits.
I don’t know how you get from what I said, to what you said. The dev was paid for the dev time, which was advantageous to him, so he took it instead of leaving. He has no risk, therefore does participate in the upside beyond his salary. The company paid for the upside.
If someone employs me to innovate for them I expect them to protect me from the consequences of failure (as long as I don't constantly produce failure) while still appreciating my results.
I mean steering the company to invest in projects that are more likely to succeed, that's just the job of upper management IMO.
I realize this is an unpopular opinion but I really think it's management's job to buffer our failures (or even better, avoid them upfront by making me work on things that likely succeed) and share the fruits of our success with me. And in that way, a stable salary isn't fair.
Of course it doesn't work like that, unfortunately.