I feel like I should justify my vote:
I say yes because I do want to fix a time in my head when this was written.
I read "Stranger in a Strange Land" for the first time a couple of years ago. If I hadn't known how old it was, I would have tossed it after about 4 pages and missed out on what has become my personal favorite sci-fi novel. I knew what I was reading, and I was prepared for some dated ideas out society, Mars, and some rather dusty-sounding language.
I would hate to think that I'd critique a story as "dated, worn, derivative," and then have the story turn out to be 30 years old, when a given trope might still have been fresh or edgy.