One essay in 37Signal's book 'Getting Real', touches on this. Especially the quote at the bottom. You can read the essey online here https://gettingreal.37signals.com/ch06_Done.php

Basically, a brilliant idea with a poor execution is worth very little, just as a poor idea with brilliant execution is worth very little.

I'm not protective of my ideas. Instead I tell people about all of my good side projects. My rationale is that even if they go out and execute on my idea, if my execution is better than theirs, it's still a success. However if they do a better job than me, that means my execution is poor and I was headed for failure anyway.