From the WikiPedia page: "Routing incoming calls is the task of the ACD system".

TaskRouter isn't an ACD in that sense.. or no solely an ACD system anyway. It is an API driven way to distribute user defined tasks. It can serve as an ACD, such as routing calls to an available agent.. or.. SMS.. or chat.. or "tickets" or whatever you define as a Task and a Worker using.. primitives. No dependence on calls.

To your point.. maybe using the ACD would help some people understand it at first glance.