Uhm, I don't know what backlash you were reading, but what I read, everyone agreed that while there was no sexual assault *in the book* that didn't made the cover any better.
I've seen a lot of covers depicting the danger of the Brood, and none of them included slimy tentacles. In fact, I'm pretty sure the Brood doesn't has slimy tentacles. They have tentacles, and they drool a lot, but that cover didn't scream 'Brood' to anyone, except those already following the Planet Hulk thing. Why the cover didn't include the Brood face? Or their claw-like legs? THAT would've made things clearer.
You keep saying that editors and artists explained that their intent was not to portray sexual assault. Leaving aside the fact that it sounds a little too close to 'you're reading it wrong', THEIR intent, and THEIR perception of the same cover doesn't mean that the reader's perception was wrong.
And yes, it was a tragic loss, that much we agree on. But don't blame the anger for one cover for that loss, as H4H was heading for cancellation due to low sales long before that. It's like blaming the Mary Jane statue fiasco for the low sales of BND. Apples and oranges.