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'.
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.