Why did it take me 10 years? Because I had 10 years less experience 10 years ago. I was a C++ developer with only a couple years of professional programming experience. At that point, Java was the new upstart with the promise of GC and libs that actually worked across platforms. I grew up along with Java and learned a lot along the way. As a professional programmer, I didn't know anyone that used anything but C++ or Java. CL was not a career choice (I'm still hard-pressed to say that it is).
I spent many years building some pretty good production software in Java and it certainly paid my mortgage and let me grow in important ways. I did tinker in the background with Ruby, Erlang, Python, Groovy, etc etc and tried to bring them in as testing tools or whatever when I could. There are still many things I like about Java and working in Java obviously makes your work available to a vast number of programmers.
I feel incredibly lucky that Clojure (and Scala and ...) are possible choices now and that I've managed to get to an experience level where I can make the judgement to recommend it and have an employer listen to me.
I do apologize for not personally making the majority of the industry use Common Lisp 10 years ago. My bad.