They're not distributing the code outside of their company, so the source license in this case is entirely irrelevant.
We could make a different argument if they were using AGPL'd code...
Now, my current employer... Email your manager: "I wrote this entirely in-house and would like to open-source it." Manager: "OK, let's talk to Legal" Legal: "OK, get at least one other person to verify that it doesn't contain any trade secrets and sign this." Upload to github. Done.
And submitting patches upstream - just a matter of code-review and sending it out. Now that's OSS-friendly.
So we're stuck: we avidly use and consume free and open source software, but can only give back code by carving off bits here and there.