You put a smiley there, but you have a valid point. Larry Elder (among others) argues that a corporation that's racist, sexist, or otherwise bigoted in its operations is "bad for business." If you refuse to hire (for example) blacks, you're closing yourself off to potentially valuable employees; if you alienate and fail to service minorities, you're limiting your customer base. If you have even the appearance of being bigoted, you'll drive away potential costumers who will no longer give you money. The actions by CBS and NBC prove this in the Imus case. If advertisers no longer want to be associated with a known (or even just perceived) racist/sexist, then the network will lose money. And if it's bad for the networks to be associated with someone like Imus... then off he goes.
I agree. And I must say, if I referred to anyone as "nappy headed hoes" at work, I guarantee I'd be out of a job a hell of a lot faster than Imus was. Free speech has consequences.