I've been mulling over vscode extension compatibility... There is a challenge there, because the API surface is non-trivial and some of it is "web-ish". I wouldn't want people to be disappointed if 60% of the plugins they try to use don't really work properly.
Also, there are nuances like VSCode exposing APIs that force the entire file to be in-memory (which is how VSCode works), this is fine but in my editor I'm trying to get extensions to work well even if the file is huge (encouraging incremental / partial stuff).
But yes, it's a very compelling vision... and part of the reason I chose TypeScript.
Thanks for the input :)