Because it is hard and costly to have a system that does that effectively, and harder and more costly to actually maintain integrity in that system over time.

It IS impressive to be doing this, at least once you're past the stage of having a few guys doing customer support.

Building an integration between a CRM and a backlog/bug tracker has some complexity. Maintaining that over several years and proactively contacting requesters back is impressive. At least in my world. :)