Okay... gotta step in here and defend book collectors... especially collectors of OLD books (as opposed to new books bought for investment... though this does apply, I guess, to book collectors in general).
First, let me just say that I don't believe in collecting for investment. I think it's a losing proposition unless you're collecting high-end items like art or furniture, or certain TYPES of books, etc. But the value of pop cultural items -- toys, beanie babies, comic books, science fiction and fantasy books -- relies too much on public whim, and the maket is just too volatile. I always tell people, if you collect strictly for investment, you're better off just buying stocks. Collect because you love the thing you're collecting! So I collect books for other reasons...
It's true, books are meant to be read. No doubt about it. The stories are why the book exists in the first place. But that doesn't mean that books can't be appreciated as objects, too. For me, and many book collectors, old books represent a direct, physical link to the past. To a time when the book was first published, and the various cultural elements that inspired that book. But old books are a finite resource... if one is wrecked, that direct, physical link to the past is broken forever. (If nothing else, we lose that great, vintage, science fiction cover art!) For those of us who care about such things, THAT'S a waste and a tragedy. Which is why we buy reading copies, too. This way, we can collect and preserve these pieces of history while still enjoying the stories.
I think it's unfair to assume that all book collectors stick their collections in boxes, which are sealed in vaults, which are then buried 500 feet beneath the earth. I've NEVER met a book collector who doesn't take pride in DISPLAYING his or her collection. (DEALERS, on the other hand, are a different story...) Sure, most of us take care to protect the books by putting them in plastic or whatever. But again, that's because we'd rather see these books survive. The story isn't going anywhere -- it remains in print, and MANY book collectors buy modern editions so they can read them. (Or, again, reading copies that are already beaten up.)
Remember, museums exist not to hide stuff away, but to allow others to see those things in the collections, while at the same time keeping those things safe. Many book collectors feel the same way -- protect old books for the future enjoyment, or education, or whatever of other people. That's why, when they eventually decide to leave the world of collecting, many collectors try to sell their books not to dealers -- the easiest way to dispose of a collection -- but to other collectors, people who will enjoy the books they way the original (well, sort of original) owners did. OR, many book collectors donate the collections to libraries or schools, with the stipulation that people have ACCESS to the books, and that they not simply end up in some dark basement.
I actually think that to suggest an old book isn't worth protecting, that it should be read until its pages fall out and its covers succumb to endless creasing, is sort of insulting to the book. I'm proud to think that there are people out there who consider science fiction books worth preserving in the same way that people consider Shakespeare's folios worth preserving. To me, this indicates how important science fiction itself has become (or fantasy, or weird tales, or whatever).
Consider:
If you dig up a bowl from ancient Egypt or wherever, are you really going to eat out of it? Scraping forks and spoons against it, washing it with eroding water and soap?
Earlier, someone compared books to a painting, saying that they wouldn't stick the art in a closet. True, but you would take care to protect your art, by framing it properly and displaying it in a way that allows you to view it but also keeps the dog from slobbering all over it.
Vintage car buffs love to drive their cars, but they also know that driving them every day, in the same manner they drive their Hondas, would end up harming the car, causing it no end of wear and tear. This would shorten the car's lifespan, and would prevent the car buff from driving it in the future. So they drive it only on weekends, and the rest of the time they keep it under a cloth in their garage.
So I think there's more to book collecting than most people here seem to think. It's not the black and white (I think there's a bad pun in there) pasttime that everyone assumes. Rather, it's a fun way to connect with books as important cultural objects, objects that changed the way our society works, and ultimately bring pleasure to people on a daily basis.
ALL THAT SAID... I do believe, as I said earlier, that books should be read -- especially hardcover books (new or old), as they're pretty darn durable and, even if you're collecting them, you don't really have to worry. Signed, unsigned, whatever -- read the darn book! Or, buy two -- the author will probably thank you for it.
(I wrote about some of the other benefits of book collecting in another thread, I won't bother including those, too -- no one wants to read any more of my ramblings!)