The issue comes when an auto update regresses something that the user relied upon. As long as the automatic update has a 'downgrade' option that's tenable but most of the solutions out there make downgrading difficult.

I prefer automatic updates that are presented to the user for action, sadly feature update/release notes are often hidden or content-free (cf. Google's apps' updates on the Play Store) and downgrading path varies heavily with OS (easy on Linux, impossible on iOS).