Why have they waited 30 years to do this?

It will just look bad compared to the original Blade Runner, how on earth do you follow up a film that is such a classic?
Im struggling to see the point in this...

Not really enthusiastic about Ridley directing it for some reason. He is one of my favourite directors of all time, but i dont feel he will be able to bring as much to the project as he was able to one in 1982.