I'm with Mordred here, yes, it was a stretch goal, no, it was THE stretch goal.
For me this is a game-seller. The only reason my friends and I weren't interested on D:OS1 was because the possibility of the editor excited us but...only pre-made campaigns with no GM.
Now we have a GM, it is still a stretchgoal, yes, but is still part of the game. It has sold more than half a million copies already, the game was funded in less than 12 hours on kickstarter. They had (and I suppose than they still have) the funds and resources to make it Top-notch. And some of the design choices on that editor are just...weird.
Not able to create an npc from scratch but from a template that locks part of the clothing/hairs, GUIs in shockwave (little bit old, i think, and hard to modify) an absurd 4 player limit for custom campaigns (I understand that limit in the main story, but for the rest? c'mon, give us freedom!) Not all the monsters from the main campaign are active on the GM and had to be activated by a community-made mod? (Come on that makes no sense) And i won't start with the excruciating difficulty to change/add new visual content and their obscure pipelines (visual effects, skin colors, textures, changing the color of...the fire paintable effect f.ex, or, geez, add new ones just by changing the color of the existing ones) when they promised us pen-and-paper freedom we have a limited hardcoded system (Just had to see these forums to read people asking to tweak, change, add or do things with skills/classes) and a system that is difficult in some details for no reason (One dumb example: picking colors for the armor, that menu is uncomfortable to use, instead of selecting the color from a list, or better, a color wheel, we have to go color by color of pre-accepted hues. Why?)

We all love the game, we all see the possibilities, but is not a crime to admit that certain things can (and should) be done better. Now is the time to say what things we DO NOT like and what things we DO WANT, and Larian will be there to listen, they have a powerful tool, with some changes it can be THE ULTIMATE tool. And some changes aren't that hard/drastic to do, most of them are just "quality of life" fixes.
But we have to yell, we have to cry, and they have to listen, they have the skills, the talent, and the resources to make this much, MUCH better.