You should have loyal visitors like webmasterworld.com. I don't think webmasterworld.com is dependent on Google. WW stays even though Google sends zero traffic.
Are you kidding? g### adores wmw. Put up a post, and it will be indexed before the page has time to refresh. That's how I found this place. Look up one thing, another thing, another thing, and after a while you notice that the best answers are all from the same site. But you can't get to that point if people don't have a way to find out you exist in the first place.
Relying solely on Google is just lazy, shortsighted and a suicidal strategy for the long term survival of a site.
Something to think about when anyone talks about "whitelisting" robots. <fe>All the important search engines are already established, so there's no point in wasting your bandwidth on the upstarts, outsiders and wannabes.</fe>