Maybe it's because I've actually built things in real life and created digital spaces in Photoshop/Maya/Unity/etc? Is it because it's the ultimate ease of use creator?
Nope, that's not it. I know lots of folks who've built things in Maya/etc. who love MC. And I've built a number of things in real life (and in other computerized building programs, like old Duke Nukem levels) which doesn't effect my enjoyment of doing so in MC.
I think you're probably trying to hard to understand why you don't enjoy it. It's okay if you don't. Not every game is for everyone.
I like the exploratory aspects as well as the simple building aspects (and yes, the simplicity of build tools is attractive, particularly to younger players) and I like the procedurally generated worlds. But it's okay if you'd rather build something in Maya than something in MC. It's certainly a more useful skill.
Note: I do all of my building in survival mode, but set to peaceful. So I don't have to deal with creepers, but I do have to mine all of my own resources and fab new materials. Seems like cheating to do it in Creative Mode. But that's one of the great things about MC, you can play it however you want.