Why do I have to worry about refresh rates and PDF files? I am the end user. I don’t really care for refresh rates and how PDFs work. I want to read a PDF in a smooth way similar to what I can achieve with the cheapest/crapiest smartphone.
You can probably notice the psychological game at play here. It seems that Apple is reluctant to put resources to fix this error cause it will probably cost money. It will probably just carry along like that and those that complained about the issue will get sick of incremental emails sent to their inboxes and at some point unsubscribe from this feed, thereby giving up.
And the problem, though still relevant and apparent, will be forgotten about.
I think that is what Apple is aiming for *if and only if they are not planning to do a fix.