i wonder why no dev wants to make a creator like modded skyrim, where i really can do much stuff.
Probably because it took 5 - 6 years total to develop, including 3 or so years of full-time active development, and all to just make the base game.
Then it took the better part of a full decade before we got to the current state of modded Skyrim CC - almost all of it done part-time at best, for free, by highly talented creatives who used a well-developed communal understanding of the underlaying framework that had been built up for as long as Bethesda had been using the Creation engine.
Long-story short, it's not going to happen any time soon. Too much time and effort is needed for a part-time passionate dev to invest on their own, and bringing on any extra hands to help means they have to be paid for - something not alot of people are willing to help with when it comes to adult games. Especially if it's over a game they wont be able to actually experience for years.