I never used LMs, but I wrote my dissertation in CL. What a monster (this was after 5+ years of Lisp programming writing a couple of interpreters, teaching it). A baroque morass, similar in X to complexity. (Btw, if you're comparing graphics APIs, X is a heck of a lot worse than the Windows API.)
To those commenting upon C++ and its metaprogramming complexity -- a lot of your complaints here really focus on the complexity of metacode WRITTEN in C++/templates, not in the template strucure itself. Even with STL, C++ is simpler and as rich as CL. If you'll exclude the paradigm shift, of course...
C++ is simpler and richer than CL? I've worked in both languages and would say the reverse. In fact, I'm stunned by this statement; I would have thought it impossible from anyone with sufficient experience in both. Our minds must work very differently!
My feeling when I started working in Lisp (CL) was that of a fish who had spent years swimming in oil, glue, and other fluids, finally experiencing water. C++, by contrast, was my wet cement (and cement doesn't stay wet for very long). While it makes sense to me that a Lisp connoisseur would find CL overly complex compared to other Lisps, I am flummoxed by the idea that anyone would think this in comparison to C++.
Programming language preference is far from rational. Not only is there a strong intellectual bias toward what one already knows (viz. Blub), there is a strong emotional bias toward what one /likes/, and that is conditioned by personal experiences. For example, if a language is imposed on you (by a professor or manager), you'll probably dislike it and look for things to hate about it. Conversely, if you discover something for yourself and associate it with the freedom to do and create what you want, you'll probably feel strongly about defending it against criticism. Of course, we spend a lot of time arguing that our emotionally driven choices are strictly rational. Such is human nature.
I don't think anyone is immune to this, and that's why working in a language that one loves will always be more important than working in an objectively better language (by some criteria).
To those commenting upon C++ and its metaprogramming complexity -- a lot of your complaints here really focus on the complexity of metacode WRITTEN in C++/templates, not in the template strucure itself. Even with STL, C++ is simpler and as rich as CL. If you'll exclude the paradigm shift, of course...