That was a case of relatively modern, scientifically enlightened people encountering a message from relatively primitive and superstitious people and - correctly - dismissing it. This is a case of potentially very primitive people encountering a message from us, advanced scientists who know what we're talking about. It's a decent comparison, if only to highlight the differences in the two problems.
This is why "Sending this message was important to us. We considered ourselves to be a powerful culture." is part of the message. If we can't convince the future that we have authority in this matter, the message will be ignored.
That was a case of relatively modern, scientifically enlightened people encountering a message from relatively primitive and superstitious people and - correctly - dismissing it. This is a case of potentially very primitive people encountering a message from us, advanced scientists who know what we're talking about. It's a decent comparison, if only to highlight the differences in the two problems.
This is why "Sending this message was important to us. We considered ourselves to be a powerful culture." is part of the message. If we can't convince the future that we have authority in this matter, the message will be ignored.