I think you're using an unconventional definition of a bounce. For as long as I've been doing analytics (10+ years), a bounce has been defined as "a user visits

I think you're using an unconventional definition of a bounce. For as long as I've been doing analytics (10+ years), a bounce has been defined as "a user visits one page, then leaves the site." The length of time spent on a single page was never incorporated in to bounce rate. What you're speaking of is the inference that is often (incorrectly) drawn from bounce rate; owed to the misunderstanding of the precise definition.