Feels like I often see it used to retire APIs that are now understood to be unsafe, insecure, or otherwise a bad practice for some reason. It gets replaced with an API that does not inherently have that problem, and the old one is in deprecated. it feels like "expressing disapproval of" is the right definition in that case. It's only there for a migration period to happen more gracefully, but its continued use is frowned upon, and not just because it will eventually be removed.