Well, according to the link below ratings certainly weren't the issue - the news/talk station, despite being on the much-disparaged AM dial. has a solid 7.3 in a 16 station market where Clear Channel has seven stations.
http://ratings.****************/cgi-bin/rol.exe/arb079
According to the news article referenced in the preceding post the Nielsen ratings weren't as positive - but had been stronger prior to a 2011 cutback. But chopping a 30 year veteran isn't likely to improve anything.
Where might Mr. Walker go? Well, his former associate and also the former news director are now over at an apparently very successful NPR AM affiliate, which is listed in the commercial ratings but reportedly would be in the middle if it was. Considering that it doesn't have WHAM'S 50,000 watts that's not bad.
CC is doing itself no favors by slashing local talent whuikle riding rghe network" with Premiere's syndicated hosts, but considering its debt load that may not matter.