I guess I'll throw in my two cents worth here, even though it may come out worth less than that
The way I view DBing is it is not passive. Simply standing by and being a doormat is being passive. Allowing the WAS to walk all over you is being passive. Allowing the A to control your life is being passive. I don't think anywhere in the DR/DB books does Michelle advocate any of these. In fact, when it comes to dealing with the A (which, by the way, I should note that only a small portion of DR/DB is devoted to dealing with an A, the rest is really set forth in terms of achieving goals in a relationship to strengthen it), we are told to ignore the negative stimuli, give up begging, pleading, pursuing and get a life. One of the other things she advocates is trying to understand what the other person is giving your spouse and endeavoring to fill that void in your R. That's where the self-improvement comes in. Communication, learning to speak the "love language" of your mate, etc.
I think DB/DR is really about doing that 180, and being the person that your spouse loves and will, in time, come to love again. It allows the natural tendency of pursuer/distancer to kick in and change the dynamic. In short, it brings to mind the old adage of letting something free and seeing if it comes back to you. In the process of seeing if it comes back to you, you don't sit idly by, crossing off the days and lamenting times gone by....you live, you grow.
"Achieve success, but without vanity; Achieve success, but without aggression; Achieve success, but without gain; Achieve success, but without force." Lao Tzu