As a remodel contractor, I can't even count how many houses I've worked on that had the original sheetrock was installed with fine thread sheetrock screws. In my opinion, they hold the sheetrock to the wall just fine. Nothing to indicate that there is an issue, or shouldn't have been used.
I don't like them myself and I never buy them, but I don't see any issue in using them.
In a pinch, I've used deck screws, Hardie screws and wood screws to do sheetrock repairs.
For installing sheetrock, I use course thread screws.