A hundred Lisp startups would bloom. ITA is the blackhole of Lisp programmers; a good chunk of them work there.
Which is my guess as well: Common Lisp is stuck in standardization amber prior to it dealing with too many things that are critical today (concurrency and network programming being the two biggest ones), Scheme is in a mess due to the mess with R6RS and moves slowly. At least it moves, unlike CL, but it's so slow there isn't even yet a standard for multidimensional arrays; at this point I expect it to continue in its niches of education and language research for a long time.
To do anything useful with common lisp I had to spend a lot of time researching which CL supported which APIs, and stuff like GUIs and SQL weren't standardised (or maybe they were, but finding implementations of the standards was difficult).
Contrast this to my experience with Clojure, where I had a REPL running in a text widget within an hour of starting to play. Sure, most of the code isn't very Lisp-y ATM but then it's mostly direct library calls. As I learn more I expect I will start using macros for things like GUI building (or perhaps someone has already created a more natural clojure library for GUIs and I will use that)
Being able to get started and productive immediately is a big win for Clojure (and other JVM based languages). Even if you don't know much Java, there are abundant tutorials and examples on pretty much any API that are relatively simple to translate from Java to Clojure.
I am a Lisper by day-job, and it too is capable of being a royal pain in the ass. Only difference is, instead of bitching about other people's code; in Lisp, I have to write the code then bitch about it :-/