Another solution is to use uBO's "firewall" to block disqus.com everywhere, and to enable (temporarily or permanently) on a per-site basis where needed with a mere point-and-click interface.[1]
Not a plugin (does uBlock / Adblock even have a concept of plugins?), but rather a simple blocklist.
Just checked, and this list doesn't block comments on hacker news or reddit, just like it doesn't block the wall on facebook or posts on a forum. It would be pointless, because the whole point of those [social] sites is the comments.
I prefer this way because uBlock Origin is already installed and is quite lightweight, so the incremental performance hit is less. I can see your point about UI convenience too. Everyone has their own priorities!
I mostly use it for blocking comments on news and video sites [in my experience typically 99% noise]. Whitelists can be added for individual sites, in the same way that any blocking rule can be whitelisted with custom filter rules.
