Looking at what it takes to actually implement the "belly of the beast" from scratch, I don't blame them.
(Also, after seeing the below 350-line function that's part of a 3113-line file, I now know that whenever I'm yelling at CSS layout behaving weirdly, there's someone with a much, much more frustrating job.)
EDIT: for anyone who doesn't know, https://servo.org/ is Mozilla's ambitious project to rewrite their browser from scratch with concurrency thought in from the beginning, supported by Rust's unique approach to safe concurrency. Parts of it have already made it into Firefox: https://bholley.net/blog/2017/stylo.html
(Also, after seeing the below 350-line function that's part of a 3113-line file, I now know that whenever I'm yelling at CSS layout behaving weirdly, there's someone with a much, much more frustrating job.)
https://github.com/servo/servo/blob/master/components/layout...
EDIT: for anyone who doesn't know, https://servo.org/ is Mozilla's ambitious project to rewrite their browser from scratch with concurrency thought in from the beginning, supported by Rust's unique approach to safe concurrency. Parts of it have already made it into Firefox: https://bholley.net/blog/2017/stylo.html