We are the Danish Moodle Partner and can see that a lot of our customers are annoyed by the inability to delete scales - in some scenarios a scale is abandoned in other cases the scales was created by mistake, or with an error.
It is not feasible to delete an already used scale or even do an recalculation if the scale had an error, since each plugin might include it's own implementation of scale. (And it will be impossible to find the tables a random plugin uses to store the scale setting) .
Therefore we propose a new feature, so that scales can be marked as archived. If a scale is marked as archived it must not be displayed on create of new activities or in the gradebook.
For activities created before the scale was archived, it will still be possible to see the original and update other fields.
Please share your input whether this a feasible approach.