I won't say I'm surprised of the reactions. Two totally different cultures, and both try to measure the other with their own moral system....which is quite impossible and results in reactions like these.
Rather than being creeped out or disgusted by Japanese culture, I'm more fascinated and interested. It's entirely different from what I got used to, and it's quite the experience to learn about other cultures. If you really want to enjoy something from another part of the world, you have to turn off your moral compass and social boundaries. If you see Doki Doki Majo Shinpan! for what it is, a game, you may actually have some fun. (and I don't mean that in a pejorative way)
Don't condemn other cultures just because they don't measure up to your "standards". For you, it may be okay to play Dead Space with a grin on your face, blowing and stomping grotesque monsters to bloody chunks, spraying guts all over the place. For somebody else, it may be okay to grope teenage-looking girls. It's not that different if you think about it.