When I listen to talk radio and a listener suggests a boycott, it doesn't matter which host it is, they ALL talk about how boycotts are meaningless and they quickly try to discourage any further talk.
Historically, boycotts have worked in a lot of cases.

I suspect that all the hosts are being disingenuous, possibly because they don't want to alienate advertisers.

Bill O'Reilly has called for boycotts on his show before - such as suggestion that Americans boycott France on the eve of the 2003 Iraq War (because the French so naively warned that invading Iraq wasn't a good idea), and it seems that his boycott call was a big flop. And supposedly he has millions of viewers. So I think talk show hosts are reluctant to call for boycotts in part because they realize it's hard to have a truly effective boycott and may make the host look stupid if it fails.

Andrew

You should listen to Lars Larson and Victoria Taft. they are both quick to urge boycotts,unless of course, it is someone they support or an advertiser, then they will give many reasons why boycotts are wrong.