I think it has to do with making them uncomfortable.
lostonearth35 wrote:
What I don't get is how fictional characters that are geeky and/or socially awkward are seen as "adorkable" when people would nearly always find them weird or annoying irl. Maybe it's because they are already physically cute or attractive?
That the fictional characters are supposed to be cute doesn't harm them, it may also be that they come off as the underdog, and a lot of people like to support the underdog as long as it doesn't make them feel uncomfortable, which a fictional character would be less likely to do. They also get to come under the skin and get to know them in fiction which 'humanizes' them to NTs.
And we shouldn't underestimate social pressure. If someone is deemed cute rather than annoying, people would likely not speak opposing views but keep them to themselves.
Of course there are also plenty of characters with ASD characteristics that are nothing but comic relief characters.