That really is untrue, ofc it needs testing, I am extremly confident that our thousands of modders could provide blizzard with feedback about how features can be improved, where things leak and so on.
The things Blizzard are using the editor for are not like many of projects that will appear when the Galaxy Edit releases, thousands modders will find flaws a lot faster than Blizzard.
I totally agree. The editor is not flawless, and will have flaws. Just because they use it doesn't mean it's perfect. All they use it for is to help design levels. The advanced features and customization are done with inhouse design software, not the galaxy editor, so it should definately be put out their for map makers to help make it even better.