Most Lispers I met do actively write in multiple languages all the time. They tend to borrow ideas from other PLs instead of loathing everything else that's not their favorite. They prefer Lispy syntax, but won't reject a language to achieve a goal - they'd pick everything - runtime, tooling, etc. and try to find a Lispy syntax that sits atop. While preserving all the remaining semantics. And then they'd argue that syntax does not make a language. Perhaps, Lispers are the largest demographic of polyglot programmers in the global community.