Is it common where you live to only have the bottle fill up? Every time I've seen them in Oregon, California, Washington, and Illinois, there's either a drinking fountain right under it or within a few steps' distance away.
Because you’re encountering bottle fill stations that don’t have an attached water fountain. Your other options (at first glance) are to complain to your public works department or to keep being annoyed by the problem, neither of which is likely to actually fix the problem.
And my experience conventions, even when they give out water bottles in the initial swag bag, is people mostly just want to grab a disposable plastic bottle.
I’m actually fine with tap water most of the time but I want to carry a bottle to sessions etc.