Generally the value that you would bring with your fix is not worth the burden you put on everyone else. There are many hobby projects with a more open attitude specifically for this reason, because they are willing to take this burden for the sake of having people feel good about contributing. Try Serenity for example. Most open source projects obviously will not have such an attitude.
I mean, we're not talking about contributors who implement a whole new feature which you hadn't planned and want you to merge it, we're talking about bug fixes, which are generally short, and their value should be easy to gauge?
Would you simply accept a random persons PR fixing a bug without basically re-doing all the work?
I know I wouldn't.
Even a simple line change (especially in huge projects like the kernel) can have unexpected consequences. Your fix might fix the bug in question but cause others down the line. It can make the code harder to maintain, not fit style guides, etc. There are numerous issues caused by these "drive by patches".
Unless you actually maintain a project or is heavily involved, it's easy to miss the forest from the trees.
Ironically, the person sending the patch is most times being paid by a company to do so (since they are fixing an issue they found) while the maintainer is most likely unpaid/underpaid.
I've had a very small experience maintaining a library and already had to deal with "bug fixes" that take huge swaths of your time and simply cannot be merged. So I empathize with the maintainer here much more than the Cisco employee that was allowed days of paid work to poke around the issue and tried to fix it. The maintainer very likely had to reproduce the bug and consider any implications of the fix beyond what the author would have by the simple fact he actually maintains that project.
Personally I think a co-authored tag wouldn't hurt, but I cannot blame the maintainer for not having that in his mind when he's focused in doing his job (which is, again, most likely unpaid/underpaid).
But I can't help but feel disgust from a paid Cisco employee bashing an open source maintainer simply because his ego got slightly bruised.
