The backing can get you publicity. If the language is lousy, though, the publicity won't help it. But publicity can turn an obscure good language into a well-known good language.
I think the bigger thing that corporate support gets you, though, is a better library (more complete, more debugged, and more polished). That is an essential ingredient for language popularity. Up through Java, it was enough.
But these days, I think that there's one more ingredient needed: Solve some problem that isn't well-solved in other existing popular languages. Go has pretty good answers on multiple threads and network services. Rust has the borrow checker. Those are useful enough pieces to gain traction for those languages.
I think the bigger thing that corporate support gets you, though, is a better library (more complete, more debugged, and more polished). That is an essential ingredient for language popularity. Up through Java, it was enough.
But these days, I think that there's one more ingredient needed: Solve some problem that isn't well-solved in other existing popular languages. Go has pretty good answers on multiple threads and network services. Rust has the borrow checker. Those are useful enough pieces to gain traction for those languages.