So what's your point? I guess you haven't even used Clojure, just looked at this specific piece of code and decided for whatever reason is not "good"?
It's as if I posted some text in Sanskrit (which I don't know) and complained that some people put Bhagavad Gita on a weird pedestal - "verdic concepts don't make your religion magically better".
Can you elaborate the heck you're complaining about? Arguing that "this FP code doesn't look nice to me, but OOP generally does", without more context is like arguing that "this French poem doesn't sound nice to me, but English poetry generally does" without understanding either language deeply.
That's just comparing surface aesthetics rather than understanding the underlying paradigms, idioms, and design principles, not to mention the fact that Clojure isn't "purely functional" - it does have object-orientation and polymorphic dispatch and other mechanisms that you've apparently put on some other weird pedestal.
https://github.com/wedesoft/sfsim/blob/main/src/clj/sfsim/co...