I agree, let's flip this around and think like customers. We go out to choose a vendor for some important service.

Vendors A and B have roughly equal parity on features and services, but vendor A's employees eat their own dogfood and vendor B's don't.

Now in one sense, who cares? Eating your own dogfood is a means to an end, not the end itself, so it's like finding out that McDonalds employees don't eat McDonalds food. As long as they wash their hands, who cares what they eat themselves?

But on the other hand, I'm a human being, and I'm personally a lot more comfortable doing business with a company that seems to care about its product from top to bottom, and isn't staffed with people who don't like their own product enough to use it.