For Drupal 8, there's no more "drush pm-disable" command to turn off modules & such (say for development sites). They now need to be uninstalled. But in Drupal 7-, "dis" automatically uninstalled dependent modules as well. There's no such functionality in pm-uninstall to do the same sort of thing in Drupal 8.
We should add a pm-uninstall option that takes care of this, something like "--remove-dependents".
The current situation is actually pretty bad, in that you can't even uninstall two dependent modules in the same call to pm-uninstall. It seems like pmu checks the dependency chain before actually attempting to uninstall any modules, so if one module depends on another only the one is uninstalled, and you have to run pmu a second time. This is really painful for any sort of CI system.
Issue #1854: Allow uninstall of dependent modules.
See #2566, I think this is actually a regression introduced by #925
Issue #1854: Allow uninstall of dependent modules. (#2566)
* Issue #1854: Allow uninstall of dependent modules.
* Updated documentation.
* List all modules to be uninstalled.