TL;DR: CouchDB is nice because reliability, no JOINs, Javascript is untyped, no SQL injections.<p>This article could fit in a Tweet, and wouldn't even exist if you took out all the non-points: SQL is reliable too, nobody forces you to write JOINs, there are languages better than JS, use prepare statements/stored procedures.
NoSQL doesn't mean No Injection attacks. Just ask Patrick:<p><a href="http://www.kalzumeus.com/2010/09/22/security-lessons-learned-from-the-diaspora-launch/" rel="nofollow">http://www.kalzumeus.com/2010/09/22/security-lessons-learned...</a>