Many companies rather not say

[szabgab]

In money/notsay.

One thing might be that they are afraid of the legal ramifications if someone gets hurt by the project or by the feature they sponsored. It is less likely that someone will sue an individual developer as they cannot expect any real compensation, but if there is a corporation with deep pockets is somehow associated with the project or with a specific feature then this can increase the risk of being sued despite the license on the project. Someone might even think they are entitled to support from the sponsoring company.

If you agree I can send this as a PR as well.

[bagder]

isn't this just speculation?

Companies do open source all the time across the globe. Do you see many of those that put their name on their contribution getting sued as a result? I'm sure it happens, but is that actually a likely reason for why they so often ask to go under the radar?

[szabgab]

This was one of the explanations I've heard. Was this the real reason? I don't know. It was also a while ago. These days they it might be different.