I think it's a because back in the day... ( pre-2000 - 2005 ) the front-end was just about css and html... not a lot about js... there was no, as today , front-end developer but a lot of front-end integrator... So the backend Dev talked about the front end a little bit like it was too easy not real programing... and that was true in that day... but now like Siddarthan Sarumathi Pandian said the front end dev is now more complicated that backend dev.