Enterprises are usually keen on buying software for big vendors. It’s reasoned by e.g. with the possibility to have support and also to get the party to blame on if something goes wrong complete software open source solutions are seldom used. Unless there’s some company between offering those 2 things (support and party to blame).
Time to time support cases for vendor requires changes to application’s code. These changes are often shared to other users as patches. So in a way if/when enterprises are paying for changes that are beneficial for the vendor itself.
Enterprises can develop something on their own. Usually, these things stay strictly in-house. Usually these application use at least partly open source components which can contain some flaws. The bad way in this kind of situations is to make the workarounds to own code. Even worse is to make the custom version of that component only for you. The easiest solution obviously for all would be to fix the component itself. But here comes the difference between big vendor software and open source components: it seems much easier to pay this kind of changes through license and support costs than through salaries. The outcome of both is still the same: benefit to all the users of component/application/system.
So, most companies are not emphasizing participation in open source projects. Most companies are using software with license costs. With licensing costs, you might get support and somebody to blame if things are not working. If you’re using the software in a certified environment. With participation to open source projects, you get support from the community. Time to time this community can even contain some quite big players as Google, Amazon or Netflix. Participation increases the attractiveness of your company as an employee.