If OPs story holds up, their employerer paid them to work on OS software and they spent time and expertise debugging and fixing an issue.
Not receiving credit here diminished the likelihood their employer will contribute employee time (money) in the future.
Also, I don't see the criticism of the OP wanting credit for their work. This is totally normal and expected.
They way I understand it, the main thing your employer cares about is getting the bug fixed / feature implemented.
In my experience, yes, companies love any way of gaining prestige and contributing to OS is one of them. For some devs it's a strong positive signal when a company they interview for contributes to OS.
There are also performance reviews to be done, where it's a positive to be able to say you/ a dev you manage achieved x.