I don't think I care, really. A long book is good for a long journey, a short one may be easier to sneak in between others, or when I take a break from a longer, heavier one. Both are good, maybe in a slightly different way.
I have read some comments suggesting that some people may be intimidated or discouraged in advance by a thick looking book. For my part, it's not something I consider either before or after reading it. I don't really know how long the e-books I read are. Paper books give you an idea, but there are other factors that may make a book appear longer or shorter (big type, thick paper...).
If I feel a book is too long, it's because the book bores me, not because of the number of words in it.
