Matt Ward's codecies are balanced against Matt Ward codecies, that is to say the codecies that are written in the new style, sure he can't write fluff that amazingly (it's still better than half the people there and has taken it in a more rogue trader direction which is always good) but he can do crunch. He is the best now that Andy Chambers has left. Robin can't write crunch, Gav can do fluff but can't do crunch. I can't remember the rest right now, but people blame ward despite everyone else writing gimped armies in the old minimalist style which needed to die because it was awful. By now everyone seems to be catching up with the style so hopefully when the new codexes get released they are more up to scratch with the new style.

Yes his rules aren't super tightly written and favour fun, flavour and options over tournament play, but that's usually how GW has been anyway. Notice how ward's demon army book isn't too bad until you get people taking demons from multiple gods and using them to cover each others weaknesses... like that would ever happen in fluff.

This can be summed up as "Don't be a munchkin and then complain that you're overpowered"