You can access Zoom meetings through a pure web interface without installing anything. The experience is somewhat reduced.
1) The lack of e2e encryption despite trying to market themselves as having secure video chat.
2) https://news.ycombinator.com/item?id=22749805 (comment in this thread - they literally phish you)
3) https://twitter.com/c1truz_/status/1244737672930824193 abusing the traditional installation process on OSX
EDIT: OK (2) may be a real system prompt - https://twitter.com/DigitalResist0r/status/12452813782932807...? I didn't see anyone else in the twitter thread claim that it was using a real system dialog, so I'd still say it was poor practice of them to have such a shady looking system dialog.
There's no malice there (on the posters' side). If Zoom does better people won't have cause for shining a flashlight on their data privacy policies or security holes. We will see if Zoom grows up fast, since the momentum towards them is already so large I don't see it changing prior to the Fall when schools might risk re-evaluating their tools.