The premise of "tl" - "too long" - is a negative. While a convention, it's also dismissive, and that's what makes me sad. It reminds me of Emperor Joseph II telling Mozart there are "too many notes" in The Marriage of Figaro.
I would prefer people said "summary" or "precis" instead of "tl;dr".
In any case, it's only one of many conventions. Another convention is that "The Atlantic", "New Yorker", etc. write high-quality short stories and don't dive into technical details. It's sad that people feel that other readers here are ignorant enough of history to need additional clues about a 150+ year old magazine.
I would prefer people said "summary" or "precis" instead of "tl;dr".
In any case, it's only one of many conventions. Another convention is that "The Atlantic", "New Yorker", etc. write high-quality short stories and don't dive into technical details. It's sad that people feel that other readers here are ignorant enough of history to need additional clues about a 150+ year old magazine.