Agreed, BHX finally gets a third daily and even then it's still not good enough. Regarding the extra cargo capacity I have seen it reported elsewhere that no new cargo space is to be sold and this new flight will be used to mop up all the extra freight lost from other airports.
Even this seemed to be a thinly disguised criticism that BHX didn't have enough cargo demand to warrant a third daily flight. Perhaps I'm wrong but it strikes me that people will always (unfairly) try and look for the negatives.