Clojure deserves a lot of respect for attacking concurrency in a totally new way, but I would not call it mainstream.

Homoiconicity is overrated; Atomo and Atomy represented better where I wanted to go, which is to adapt notation to the problem, even have it be flexibly remapped and recombined per modular scope.

I'm not sure Clojure has even matched the "Lisp high-water mark" of '80s Common Lisp, which I'd consider only quasi-mainstream. Though it is definitely more vibrant in 2014 than the others.

That's difficult. Symbolics alone had a billion dollar revenue in the 80s (sum of the years), with a maximum of 1000 employees. Then there were TI, Xerox, Franz, Lucid, LispWorks, Intellicorp, ... as companies. I'd guess that Lisp earned in direct sales around 2-3 billion dollars in the 80s... In a much smaller market. Inflation adjusted that would be 4-6 billion dollar today. A large Lisp company today might employ 20-40 people. Large user groups in companies might have less than hundred employees (like ITA/Google had (has?) a few years ago).

Wow, I never realized Symbolics was that big. Were they just not able to keep up in the era of cheap, commodity hardware for workstations?

A lot of that, a lot of NIH, and a lot of bad behavior and very bad management.