It's never really caught on though, I would guess due to inertia. Most Lisp programmers just get used the parens, and maybe those that can't end up not using Lisp.
Change your IDE's color scheme so that parens are rendered in a low-contrast font color. The parens will be less-obvious.
Emacs' automatic indentation to The Proper Place is tremendously useful. I find Lisp's indentation to be just as easy as Python's, for example -- likely as I have used a Lisp for six years before coming to Python.
Once you've used it for a while, you don't think of it as much different from using {} for control blocks, () for method calls, and [] for array indexing in other languages. For me, the parens "go away", in that I follow the program control flow more by indentation than by counting parens.
It would really open up the list world, especially to those of us comfortable with python.
It seems like such an obvious upgrade to me, since:
A: In no case will it break code that works now.
B: It would always be possible to translate to and from it unambiguously, so if a team wanted to keep all of their code one way or the other, each individual developer could still see things with their own preference - imagine a tool like `gofmt`.
Once I make a serious foray into Lispland maybe that'll change...