Starcraft 2 (which i assume you mean by "new" Starcraft as the original was well prior to warcraft 3) has had the Galaxy editor available since the early beta as of April 2010 even well before the full release in July. It is far more powerful including its own scripting language on top of the warcraft similar style GUI; granted a little too powerful to the extent it wasn't as accessible to newer mapmakers.
MOBA games like Dota 2 have the hammer level editor. Starwars Empire at war rts also has an editor although produced by a different company. Roller Coaster Typhoon is essential an editor as a game similar to Mario maker. You could even call ana 'sandbox' game like minecraftMinecraft to be an in-game editor. https://en.wikipedia.org/wiki/List_of_level_editors is a list of over 250+ games and their matching editor's, many of which are build it.
Perhaps its as simple as people these days rarely have an interest to dive further into the programs directory past the initial 'launch game' appapp; and with that current trend why go further to release something that is less and less likely to be used by the public.