Lets start with one thing- this anime is centered around the relationship of a brother and his younger sister, and their feelings for each other, that change and develop throughout the show (very slowly if i may add). The anime also has a mention of the otaku culture and some other stuff, but the main focus is around the siblings (and otakus.. mostly since his sister is one).
Now then. Why is the relationship between siblings is considered taboo in our society? Answer - mainly because of fear of of pregnancy that has a higher chance to result in a defective child. And that's an adult reason. And this anime is not an adult one. See the problem here? So yeah, this anime doesn't have the correct platform to deal with the problem it is centered around (not being adult), as well as the guts (as far as i see it) to deal with it. Therefor it DOESN'T. So basically as i see it, the main focus of the anime, is left unsolved (or solved half heartedly, as far as i see it).
Leaving that aside, most the female characters (including the heroine) are horrible (aside from Minami and Ruru). They are violent, bad mouthed, shallow and generally obnoxious. The protagonist on the other hand is a complete wimp (at most times). He gets randomly beaten, is constantly verbally abused, and can't (or maybe doesn't) do anything about it. This leaves me with a feeling the anime was aimed at masochists.
Now don't get me wrong, it was not that hard to watch, and i can say i somewhat enjoyed it, but the fact it has pretty much no closure, and shamelessly dismisses the main problem that was the focus of the frigging show, as well as the obnoxious violent heroines and the floor mop that is the protagonist (that pretty much got screwed over in the end too, ) just didn't leave a good feeling after i finished watching it.
This reminded me somewhat of "yosuga no sora" 's last arc, but in a bad way, since "yosuga no sora" tries to leave some sort of closure, and attends the problem more properly, even if in a dysfunctional and dead-ended way, here its simply left blank, with a bit of a sour note, as the three or so remaining love interests (two of which are viable, because one's a fucking psychopath that i'd definitely choose a sister, no, a frigging DOG or insect to marry over just to avoid getting fucking stabbed) turn away from the protagonist. So overall, i consider "Ore no Imouto ga Konnani Kawaii Wake ga Nai." as a somewhat boring and pointless watch. I do admit it has some good moments, but considering how much things i didn't enjoy it had, i personally don't recommend it.
