Can any small time writer submit their short stories as a movie script and sell them off, even if they have no experience with writing scripts before?

Submit—?

Yes—although in most cases they won’t get read by anyone.

But “sell”—??

No reliable chance.

A screenplay written by someone with no experience is highly likely to be very bad.

Are people really deluded enough to think that a multi-billion-dollar industry can be infiltrated by someone who has no idea what they’re doing—and be a success?

How does that work in the mind?