It does seem like something motivated more by a desire to make it exist than a desire to use it. Also to have a project where both your program and your programming language are lispy.
The author has stated in Reddit that their goal is able the insta parse library.
Re:Cloture: Clojure in Common Lisp
by ruricolist on Friday February 14, 2020 @02:32PM
(#22329521)
I have actually reached the point of being able to load Instaparse.
Beside the obvious: cloture is a parliamentary procedure to end debate on a subject, and I would like to end certain debates. Yes, Common Lisp is “modern.” Yes, Clojure is a Lisp.
While this doesn't actually explain why the person started the project itself, it does shed light on one possible explanation.