I do think something must be going wrong based on how few there are throughout the leagues - that's where I agree with you rather than saying "this white manager doesn't deserve it." Sorry if I alluded to it rather than saying outright where I was in agreement.
In terms of black managers who should get a shot, Ashley Cole came across well in the FA Cup coverage and apart from the Cashley Cole thing from ages ago I can't see any reason why he's not being rumoured for jobs. There will be a lot who haven't got the profile but have all the right stuff just the media aren't paying attention to them yet.
On the flip side, Sol Bamba will get a job soon (either here or at Middlesbrough) but I've not heard anything said about his tactical knowledge and only a bit about man management skills so for now I'd put him in the list of "ex-pros jumping the queue" rather than known managerial skills. With his connections, depth of thinking (demonstrated when speaking about social issues) and charm I'd currently back him as a DoF before a manager.