If his question were taken literally, then that might be a good explanation. But it seems pretty obvious that he is asking why it isn't more widely known that something so important was lost.
Two potentially instructive responses might be "The lost Apollo 11 tapes have been all over the news and everyone except you knows about them" or "NASA only recently admitted this embarrassing fact and it was released on Sunday morning to minimize media coverage."
BTW, I didn't downvote until his comment was briefly at +2; it wasn't a bad comment, just a vague/rhetorical/possibly-paranoid comment I wouldn't want to encourage.
If he had clarified that he was wondering why it hadn't gotten more coverage, I would have pointed out I remembered a bunch of coverage a few years ago -- coverage that even yielded a Wikipedia article, <http://en.wikipedia.org/wiki/Apollo_11_missing_tapes>, with a 3+ year edit history.
Instead, he seemed genuinely interested in why someone would have disliked his comment, so I gave a likely answer.
Two potentially instructive responses might be "The lost Apollo 11 tapes have been all over the news and everyone except you knows about them" or "NASA only recently admitted this embarrassing fact and it was released on Sunday morning to minimize media coverage."