This issue came up in chat yesterday, based on one of your examples.
My guess would be that they're easy to check, especially those where the answer has already been accepted by the OP.
Yes, I do think this is problematic. Your examples should count as 'link-only' answers and I was surprised I didn't see the most recent one in the review queue for low quality posts. As I said in chat, I think a good answer should not just include what but why as well.
I think there already are enough mechanisms in place to show our approval or disapproval with an answer.
What we might need, is consensus on whether a story-identification answer should be judged on different standards than other answers. This has been discussed before, albeit from the opposite point of view. All answers there give a minimum of more than just the (linked) title. So perhaps all we need to do is point 'offenders' to that, or add our own more detailed answers (which I decided to do, as community wikiwhich I decided to do, as community wiki).