Currently if a bar graph does not contain values for a label the bar itself does not display on the graph. Users would like to see a graph's label even if there is no data for the label.
Generally speaking being made aware of the absence of data is just as important as the presence of data.
As an example when looking at a count of projects per phase / stage, if there are no projects in planning the label for planning does not appear which can be overlooked in comparison to showing the label with a zero count and posing questions like "why are there no projects in planning?" and "should there be projects in planning?"
Another example would be when looking at a count of projects per project manager(or another field indicating responsibility).When we don't show the label one overlooks the fact that a project manager doesn't have any projects, by displaying the label it is immediately brought to our attention.
A few more examples that show value in the absence of data are seeing no value for a month in a revenue per month graph, seeing no progress issues on our projects when viewing a count of issues per type (when our projects are behind in progress) and lastly why are there no more work items that are user facing on the backlog when looking at the number of work items per impact.
Allowing for this enhancement would prove beneficial in many scenarios similar to the above and would prevent the need for hard-coded custom reports/dashboards that are not maintainable.