That's the joke, but it's really not true.

You can write unintelligable code in most languages.

Perl's syntax is fine, and you can write beautiful code with it - but it will also let you write fugly code that works.

I think those who say this seriously just don't understand Perl, or even programming generally. (Whilst I like Perl, I'm also proficient in C, Java, JS, Python, PHP, Bash and probably a few more, so I'm not just promoting the only thing I know.)