BSs can't mount CDs...and shouldn't...as there are more than enough other craft that can do so and are DESIGNED as interceptors.
If you're referring to the fighters...either they can't CD the novas because A) they suck B) they didn't mount any or C) they didn't know that they could.
In any case...this guy seems to be whining because they are SNACing his BS...and those can't be intercepted.
Get some skilled fighters for cover (maybe HIRE some if you have the money) and your BS will survive longer against bombers.