Average programmers don't learn Java because they're deeply interested in increasing the quality of their craft. They learn Java because it's what they were taught in school and/or because it will get them a job most easily. The bottom 80% of the programmer bell curve really doesn't give a shit about what kind of tools they use, as long as it keeps them employed.
When you get to programmers who really love programming, who want to write the best code possible and are willing to go out of their way to learn tools with very little chance of landing them that next corporate job, you're most likely in that top 20% already. So anyone who has learned Clojure, or at least can explain rationally why someone would want to learn Clojure (ie understands the benefits of functional programming), is probably not a benchwarmer idiot.
As a hiring founder who has absolutely zero interest in hiring below that top 20% (really, below the top 5%, ideally the top 1%), and has limited time to peruse a thousand basically identical resumes, applying a filter that gets rid of 80% of potential applicants is a Good Thing.