Yeah, but the same holds for private parties, too. If fifteen of us wanted a hood, we could easily contract a fiberglass shop to take a mold of the existing one and fabricate up a bunch of them.
The problem is that fifteen of us don't need a hood insert. Not today, at least.
That said, there are certainly cases where the economies work. One of our members is casting OEM-replica roof rack parts and spare tire compartment screws that are better than the OEM and probably cheaper and more available. I'm just not sure if the hood insert counts.
Could we get 15 people to do an OEM hood insert? Maybe. That's a nice way to resolve the cracking issues. But could we get 15 people to do a carbon fiber hood insert? If you're already doing a custom casting, you might as well go further... you know?