NOTE: This is going to be a bit of a rant, but I'd rather post it here than any other anime site.
I ended up having a glimpse of the 'reverse-rape' scene and some comments on it, and I just ended up getting mad. One comment said essentially "it would have been the best of the season, if it were animated properly." Which made me think, "are there people who actually think anime like To Love-Ru are sexy or well-animated?" I guess this says more about my own aesthetic preferences than anything. I avoid watching anime that use baseball size eyes and ridiculous proportions. And that guideline has served me pretty well over the years.
Arg, I just feel like the people who are criticizing this anime are criticizing it for all the wrong reason, or don't realize their own biases going into it, or they bash it just because it is being creative and taking a risk. Maybe this says something about consumer entitlement. For example, apparently some people stopped reading K-ON when they realized that the girls might have boyfriends. As if the readers were entitled to have the story play out in a certain way, which meets their expectations or biases. I imagine that some people are criticizing Flowers of Evil for not sticking with the style of the manga, but this just goes back to the whole "manga vs. anime" debate. The viewer/reader shouldn't feel like the creators owe them something to make the anime a certain way or tell the story in a certain way.
With that said, certainly we can discuss how various creative decisions impact the overall storytelling and what themes are brought out. And it would be interesting to see if someone could present a good argument for why rotoscoping negatively impacts the story of Flowers of Evil. But so far the criticisms of Flowers of Evil seem very shallow.