[karthink]

> I read some arguments against moving emacs to a multithreaded model, but I don't really remember them.

Everyone including the maintainers would like this to happen. The arguments against it are technical hurdles. Emacs is a large ball of global state and the lisp evaluator hooks into everything, including the display engine, so it's not clear to anyone how to disentangle things to the point where the interpreter lock can be released.