My use case is, I have a primary application that connects to the DB, most users work through that (setting is useless for this scenario, app manages it's connections well enough). I also have a number of internal users who deal with data ingestion and connect to the DB directly to work, and those users sometimes leave query windows open for days accidentally. Generally not an issue, but would be nice to be able to time those connections out.
If there is no big impact, I think we might add it builtin.