To add to another comment, my company is not really afraid of it, but the amount of overhead needed to contribute to OSS projects is very high here.
Basically, we have to ensure that we are releasing clean, well documented code, with proper contribution guides, that a person here can “own” with updates. Any code beyond bug fixes we push would have to be approved beyond our normal code review process. We don’t want to have our Junior Intern Dev start pushing code publicly that makes our code look bad…. Or our senior devs hah.
Finally, GPL makes things tricky for us, as we take the license seriously. We tend to release code in a more permissive license for that reason, and actively try to use MIT/BSD for that purpose. So we have to be careful, and it is much much easier to just not release code into the wild.
Oh and for new projects, we have to justify why we should make them publicly OSS - will it actually benefit the community in some way?
They were depending on you not knowing, and that is never good for you
It's most often done for the sole purpose of retaining the ability to more easily profit off of your work. When you open source your software you are basically taking the most straight forward profit model off the table. Some projects do of course manage to still make it work, but only when the user base is composed of tech-savvy enthusiasts. If you're open sourcing a desktop application targeted at the average user, like a game. It's never going to work unless you hold something back (e.g. art assets).
We need to stop with this false narrative that developers choose to keep their software closed sourced for malicious reasons. The truth is that profiting off of FOSS software is inherently difficult.