I can see why there can be confusion in having MB and DC as the F1 commentary team when neither of them are what we would class as "proper" commentators.
And this is where the BBC can be pointed at if this way of presenting the sport wont work. With some of the other sports that the BBC cover, Athletics, Cricket and Snooker, they've been employing people who have been in those sports to talk about it rather than the usual way.

Steve Cram (#362)

Steve Cram for instance, is now the BBC's main Athletics commentator, having been an 800 and 1500 Meter runner and somehow not as good as Seb Coe, starting out being the analyst on Eurosport and Channel 4 (UK) when they had the track & field sports.

Dennis Taylor, 1985 World Snooker Champion and more humorously known as the wearer of upside-down glasses, is also the BBC's main Snooker commentator.
The BBC making Brundle and Coulthard their commentary team is down to some logical process that "It's worked in other sports they broadcast, it will work this time around" but Aside from the long-distance races in Athletics, and possibly the final rounds of a snooker championship, the sports that Steve Cram and Dennis Taylor present are very "Stop-start" and "Anyone" can commentate on them (you can argue this).
Maybe I'm seeing this in a negative light, but seriously, how positive has F1, in general, been these last few years?
"The worst part of my body that hurt in the fire was my balls" Gerhard Berger on Imola 1989