FW vendors have to deal with OS bugs all the time. Let's say I'm a fW vendor and I have this super nice network card that doesn't work with RHEL or Windows or whatever, just because there's a bug in the OS. Well, Red Hat or Microsoft couldn't care less about it, it's MY problem and it's MY loss that I can't sell my shiny peripheral because the OS is broken, my company's going bankrupt and I'll loose my job. So in a world that FW vendors need to make things work, yeah, they pretty much need to implement workarounds over broken OS or broken HW (been here, done that).
And even if you say "but Linux is open-source!" and submit a patch (been there, done that) it takes quite a while from the moment you submit the patch to the moment the servers are upgraded with a newer kernel. A workaround fixes things *NOW* and makes that angry customer go away.