There are many reasons, the one "to hold something" is but one. I really love to read and while I also love flipping through wikipedia articles I prefer reading from paper by far over reading of a screen in case of very long texts. Also much of the information to be found in the internet must not be quoted in scientific discourse (e.g. the papers I got to write for the university) while these books (though these particular specimen provide basic knowledge rather new theories) are perfectly suitable for that purpose. Many of the pictures from the book have so far not even been published online (yes, that IS possible even in our time
).
While I am definitely going to read those books (unlike those people who buy tons and tons of books just to have them on their boards but with no intention to ever read them (some will even go so far to buy fake book spines to put on their boards in order to pretend being erudite to any visitors; which may turn out highly embarrassing if anyone ones to check out one of those "books")) I admit it is something about collecting as well it looks great to have a whole series of these books complete.
It is not like I was going after every book I could get my hands on. Not even after every book on one of "my" topics, but I knew these to be very well made and written (knowing a couple from the series from libraries which never provide all of them though).
Some say that the day will come when electronic reading will oust books, and while the book selling rates so far do not support this view, I'm afraid there is some substance to it (Time life for example has by now stopped creating such books as ever less people are willing to pay for them), but I do not hope to see the day when it is just screen reading only. I reckon it may be as difficult for you to understand as for me the collecting of computers would be, somewhat understandable but not quite sensible. That sensibility in our actions (or lack of the same), I reckon, is strongly determined by the perception of the individual
