Earlier quoted context omitted.
Children growing up also don't like people condescending and treating them as the children they are. If a child puts on the appearance of being an adult, should we treat them as such and give them the rights and responsibilities of being an adult?
treating a child like an adult can lead to them acting like an adult and accepting responsibilities they otherwise would not, where as condescension re-enforces their role as a child
It's like the debate about praising children for their innate abilities (let's say: intelligence) and behaviour (let's say: trying many times to solve a math problem even if they fail at first): the first approach put them in a fixed mindset while the second ease them into the idea that they can try, blunder and try again and that's what makes them getting better (not an innate ability).