I interpret "Lisp" to mean "any Lisp," since none of the reasons he gives are really related to CL in particular.
(I think the actual answer here is: mindshare. Respondents heard Lisp and assumed CL, maybe Scheme.)
It is also specifically noted that Lisp programmers who use Lisp part time have right to write why they do not use Lisp - when they do not use it.
There is a huge variety of reasons and ways people think.