He's spent 35 years in St. Louis radio, the previous thirteen of them associated with KTRS (550 AM). So the fact that his retirement comes on the heels of KTRS losing the Cardinals to its original radio home of KMOX is just a coincidence.
http://www.bizjournals.com/stlouis/news/2011/02/28/ktrs-founder-dorsey-to-retire-as.html
http://www.bizjournals.com/stlouis/news/2011/02/28/ktrs-founder-dorsey-to-retire-as.html