Like most such list you have to suspect a lot of voters are not really scfi fans. There are lot of good books on the list but there are some that I would guess people are just voting on books they have heard of but never actually read or voting on the very few scfi books they have read like 1984. Take "The Moon is a Harsh Mistress" great book for it time but try reading it now, not that impressive. Same with the Asimov series and Phillip K. Dick. I have read "Do Androids Dream of Electric Sheep" and if they had not made it into a movie I doubt it would have made the list. I still have to wonder why people thought Snowcrash was worth reading and the true scfi books are heavily weighted to classic but overall it is a good list and I have either read or want to about 80% of the books on the list.