when designing an icon or logo with mass appeal, I dont think that relying on the basics of form, proportion and focus will come to a close.
Might want to reread what I said. We're seeing now many more brands with which their main logo cannot be printed b&w, what happens is a separate version is created for those situations. Generally a simplified, often silhouetted version. That doesn't mean they're ignoring form, proportion, or focus. It just means that brand designers and agencies are no longer constraining brand appearance to contrasts stark enough to work, without modifications, in b&w--and that's due in large part by the massive drop in the price of printing and the growth of brands in which the screen is their primary market face.
It's still a great idea to go b&w during the design phase as a tool, no one is saying it's not. Just like viewing at multiple distances, against different backgrounds, etc. are all good ideas during refinement.
edit: That doesn't mean it's the right approach for everyone but it's a trend worth noting that developed in the last 7 years or so.