Companies don't, as a rule, do this in software either. They make projects open source or contribute to open source projects because it's good for them. This is just as true in other industries. This is how every industry standard and protocol or similar works. It is beneficial to the participating companies and does not threaten them.
It's not that they don't benefit from collaborating, it's that they don't benefit as much as they could by demanding a royalty or licensing fee. Why shouldn't they? Everyone expects to be paid for their services. They're leaving money on the table for the benefit of the public at large.
Most of the "open" standards from other industries that I'm familiar with require a license, and certainly aren't open to participation by anyone and everyone. Let alone allowing you to modify and redistribute them.
But in software we've created a culture with different expectations. And I don't think we should take that for granted.
