you know, this video, there is a few things that concern me.
Namely, its not enough minecraft/terraria, and entirely too much just dev tools.
Add/delete tools. AI scripting tools. They explain the game as the same tools they are using to make EQ next. well, we have seen that before. many games have build tools like that. Neverwinter, dragonage, etc. heck even Warcraft/starcraft etc.
These overly complicated campaign creating tools tend to be a bit too confusing, and involved however, and rarely take off to a massive degree.
Its ENTIRELY possible, it is simply a UI issue. I mean, clearly some of those I just mentioned DID have some crazy modding, using these dev provided tools. Dota, etc was created right in game, using these default tools.
on the other hand, buying/selling/trading of materials in a minecraft type world is very interesting.
Materials would need to be consumable I think.
I mean a problem in these games tends to be, its very easy to just get everything you need, then give stuff for free, destroying progression for others.