What are their objections?
Note that, as a user, this is one of many quality of life things that makes interacting on a discourse powered forum smooth.
Also: on longer topics with infini-scroll, it’s pretty much essential. I don’t have the crutch of manually binary-searching through the pages until I roughly find where I left off.
If I ended up needing to interact on a forum where someone had managed to turn this off, I’d have (Public!) Words for the site admin.