This is the down side of one side being primarily (or entirely) defense.
[Takes off CM hat]
No, in this case, it had more to do with the Allied plan and Allied execution of that plan. Allied plan called for groups of bombers to attack two targets sequentially. This allowed 8 targets worth of German defenders to focus on four attacks. Second, since some of the attacking units chose to attack one target, rearm, then return for the second target meant that the disparity in aircraft was even more pronounced, as defenders from some objectives were vectored in to fights at other targets, and were still able to get back to defend their primary target.
Had the Allied attacks all been near-simultaneously on 8 different objectives, the German defensive aircraft could not have concentrated like they did, without giving the Allies much easier access to some of the targets. There are a couple of other techniques that would work well in this setup as well.
[Puts CM hat back on]