One gets a maximum of 60 days, that is all. Through a snap proxy it's possible to hold off longer, but then the proxy needs to talk with the snap store periodically.
Why people are upset is, I believe, that Canonical forces people to accept any and all changes to the installed software, without being able to guarantee perfect backwards compatibility for all upgrades. Obviously, neither Canonical nor anyone else can make that kind of promise for all software out there.
Canonical should not force updates on people; let people take care of backwards compatibility; let users turn the auto-update on and off and allow users also to freeze package versions (and their system configuration), if the users so please.
Also, not sure I understand the point about automation. There is automation already today in Ubuntu through autoupdating .deb packages. It is nothing inherently new in Snaps.
One problem with measuring Linux desktop installation base is that Linux users are often the people who turn off telemetry, call-home, employ DNT, run ad blockers, run third party script blockers, and so on. I wonder how much this skews the results.