However, since I failed to contribute to the discussion, let me add my two cents.
A midwith is in my opinion someone who is a try hard, but also a person unable to come up with original thoughts of his own and then to elaborate those thoughts to a wider audience, be it a small group of people or an online audience. These people still desire to have "intellectual" discussions and perhaps even debates, but since they have no original thoughts, they adapt the thoughts and ideas of other people who are actual thinkers. /lit/ is a perfect example of this, usually midwits will post bait titles and/or images with some snarky remarks to defend "their" ideas, which they totally didn't just pick up from somebody else. Often I see people debating whether Berserk (the manga) was influenced by Nietzsche philosophy and they probably do so after having watch some YouTube video on that topic and not after having read one and the other work, more often than not they've only read the manga and nothing from Nietzsche, but having their consumerism acknowledged as something profound makes them feel good about themselves and by extension more intelligent than others. Similarly in my society, people that work for the government and try to act profound, go to the theater where you can see low quality comedy enactments, worse than the average sitcom, but they go regardless, to show how cultured they are. So yeah in the end I'd summarize that a midwith is a try hard person, in need of attention and someone wanting to conform to social norms, but considering themselves superior to the lowest level plebs, whilst just consuming slightly more critically acclaimed content. A truly intelligent person, which I don't claim to be, I'd say that I am a midwit myself most likely, is someone who doesn't act upon emotions and does something for the rationale benefit of what that endeavor may bring, without the need to justify or mystify said act, for example:
>I go to the theater because I am a cultured individual and want to enjoy more profound entertainment
Smart and (ironically) dumb and honest people:
>I go to the theater because it's fun and I can meet new people sometimes.
Basically once you stop rationalizing you stop being an obvious midwit.