This will be an ongoing issue for instructors using Rubrics unless there is either a prompt to alert instructors about what the lack of a zero value means (when using points), or the rubric calculations provide accommodations for the lack of zeros in criteria levels (again, if using points). I can't see many (if any) scenarios where someone wants a calculation without zero values to come out the way it is built if they aren't using scales.
For administrators, I've created an ad-hoc sql query to use in Configurable Reports block plugin that finds rubrics that contain criteria that lack zeros. This can provide a safety net to engage instructors that may have this grade-integrity issue and don't realize it.
https://docs.moodle.org/28/en/ad-hoc_contributed_reports#Rubrics_without_zero_values_in_criteria