Businesses have a core mission. If you open a piece of software then you would need to have someone to support it internal to the company, it increases company liability, it increases distraction, and to justify all of those downsides it would have to have a clear upside.
The other problem is that companies are short term. Even if you could demonstrate all of the above, this could not be sustained for very long. Priorities would change and personnel would be reassigned or move on. Keep in mind head count costs are very high for companies. Moreover often head count is harder to get and maintain then the $ it represents to the company. By this I mean you might think head count is just $ on a project, but generally in terms of getting resources head count and $ are totally separate things.