It's actually quite interesting, that SQL, the language based on declarative paradigm could gain popularity. It's different from imperative or object oriented, but people liked it. Now take a look at functional programing, it's also different, but people are mostly afraid of it. It's also interesting, that Prolog, the langage, that also based on this didin't gain popularity and failed into oblivion. Is this only about people mindset? Can non-mainstream paradigms gain popularity? Do we need new ones or should we study existing paradigms and focus on theirs similarities?