If he chose his example without consideration of idiomatic Perl, then his attempt appears even worse. Further he chose to remove all spaces from the example, presumably to demonstrate that Perl code is "not clear".

I have not written a single line of clojure, and don't know how idiomatic clojure looks like. I tried to translate his example to clojure using my very limited knowledge and looking at the examples on ClojureDocs site:

    (sort #(compare (second (re-matches #".*([aeiou]).*" %1)) (second (re-matches #".*([aeiou]).*" %2))) %)

I am sure this is not idiomatic clojure, and probably a very bad way to write. If I cited this as an example of typical clojure code, then I'd be making a totally unfair judgment.

The funny thing is, when I just add spaces to the Perl code segment, it looks quite readable to me. But then, I probably know more Perl than him.

    sort { ($a =~ /([aeoui])/)[0] cmp ($b =~ /([aeiou])/)[0] } @_