I just had a contractor call me because our plan view showed an extra tread and riser as compared to the section. It happened because it's a concrete monolithic stair (which must end with a tread at the top) coming up to a concrete slab. Having the tread at the top created an additional line on the plan and the contractor interpreted that as a riser.
Yes I know line work can take care of that, but that has to be done in each and every view. If stairs could be joined to floors then it would take care of every plan and every section view project-wide. It could really save us a lot of time and grief if this were possible.