A year ago they architected their system to not uninstall when you asked it to uninstall, and instead it left a running daemon that would re-install as soon as it saw a relevant URL.
This isn't a scaling, usage, or whoops issue. This was intentional.
Maybe. I've got enough uninstaller logic wrong in my day to believe it possible that a failure to switch off all your daemons and delete them is just sloppy software engineering on a piece of the system that isn't considered critical path by product managers.
After all, users never want to uninstall our software, right? That implies they don't love our product. And of course they love our product. ;)
It's not that uninstalling isn't an important feature. It's just that at crunch time, project managers will pull people off polishing the uninstaller to put them on that virtual green-screen feature 10 out of 10 times.
This was clearly not an accident, but a dark pattern.
There are way too many complex dark patterns which have been exposed to excuse them as oopsies. This is a company where product managers overruled developers into creating security-breaking implementations for the sake of "usability".
You just described exactly what I described, only attaching a malicious connotation to it.
It doesn't have to be malicious; the fact is that the market simply favors usability. Optimizing for the things users care about over the things they don't is the first PM guideline. This has been demonstrated over and over and over again; have users first, then worry about security and privacy.
What you originally described (or proposed) what that it may be a simple case of accidentally overlooking a bit of tidying up during uninstall.
What I described - the problem that came to light March and then June last year - is that Zoom installed a web server on your Mac whose sole purpose was to silently re-install Zoom if you a) uninstalled zoom, and b) later clicked on a zoom link.
There is nothing about it that could be attributed to 'getting uninstaller logic wrong'.
This isn't a scaling, usage, or whoops issue. This was intentional.