Many reasons. S-expressions would be the least of my worries. Java is dying, not on the whole, but certainly in mindset of people who are picking new languages. It’s integration with OSs, which Clojure depends on, is arcane by today standards. Second, it’s tightly controlled by one person, and they happen to hate types. Similar to CoffeeScript, couple years after the language inception people figure out that they miss types. Adding them back in is super tough.

And third, abstractions have costs. There is no wide-spread popular LISP, and people should really ask themselves why. We have lots of code generation, and depend on it more and more. But it’s “simple” (or “primitive”). It’s usually one step. You can read the input, and you can read the output.

I’m starting to get a sense that macros are like currying. Elegant, beautiful, powerful. But net negative if your concern is to get lots of people to create software together.