I think there are two issues being discussed here:
1) That the overall power level of 40K is too high. This, I tend to disagree with, as I personally see ridiculous power levels as part of the appeal of 40K, especially when they're executed in interesting ways. Besides, it's relative strength that matters.
2) That BL books' final battles are decided by brute force and not trickiness. Honestly haven't thought about this, so don't know how much of an issue this is, but that seems to be the heart of the criticism.