The two things that stunted Java from a creative-projects perspective were (a) nobody built a native (x86 / PowerPC / etc) compiler for it early on and (b) the UI class library was utter garbage.

(a) People got way too enamored with the runtime possibilities and didn't see the opportunity to replace C++ -- by the mid-90's the serious C++ footguns were certainly widely recognized -- with a better language.

(b) I still don't know why anyone at Sun thought AWT was acceptable. They literally bought a superior class library from another company and threw it away. And every attempt to fix it became this endless parade of crap grafted on top of AWT.