I can't speak for others, but except when there's an urgent bug fix in a dependency (and I wouldn't class this bug as urgent to fix), I use the tools provided by my distro, which I update every 2 years. The version of help2man that gets into a distro will be maybe 6-12 months older than the release date. So on average, it might take 18-36 months between the fix and my getting my hands on the new version of help2man. After that, it would depend how long it was until the next release of any particular project.
Personally, I tend to look at projects I maintain once a year or so even if I am not actively developing them, to see if there are any fixes of this sort I can make.
Anyway, my attitude to these sorts of bug is that it doesn't really matter how long the fix takes to percolate; it will eventually, and at that point someone can notice and remove the upstream workaround, maybe in 5-10 years. In the mean time, it's causing a little bit of work, but it's not a serious problem.