Actually, some older sci-fis were fucking spot on. Ever read Ender's Game? I don't know about the future, but Orson Scott Card totally predicted laptops and home computers way before their time. I could name a few others.
But, yeah, modern writers can't think up shit. They always try and improve stuff instead of starting from scratch, taking from the base ideas of stuff. Wow, that sounded weird, but I hope I got the jist of my point across.
But, yeah, they could use some work.