I find the response weird because the commenter had an unwillingness to do free work for a company yet publishes a package that fixes their mistake.
Writing a bug report is work.
Writing the shim is work.
The bug report doesn't fix the problem right away. The shim fixes the problem right away.
Reporting the bug will cause a fix for everybody eventually. Adding the shim will fix it for me.
If we want to be nice to Apple - and get rid of the shim eventually - sure, we write a bug report. But if we can fix it before reporting, that gets priority.
So to me the unwillingness to help Apple with this is not a strange response. Especially considering Apple made Safari closed-source.