Who says this is actually improving their ranking? SEO is smoke and mirrors. I wouldn't be surprised if this whole exercise was actually counterproductive for them, and they just don't realize it.
Not always smoke. If you have enough resources, you can make research and test hypothesis. Also, sometimes there are leaks, like a leak of Yandex source code, which disclosed what factors were used for ranking.
Yep. Also, the days of the "Advanced Search" page have passed, but Google still has time range options under the "Tools" button near the top of the results page. If they're giving the user the option to filter results by time, then it's pretty goofy for the algorithm to de-rank a site in results where the the default of "Any time" was selected in the query just because the site has old articles in the index.
I'm afraid that, as so often with any topic, the vast majority of users never or rarely uses the time filter and so everything gets optimized for the users to dumb to search properly.
In this case I'm not too keen on blaming users for this when the option is sorta buried in the current design. The Tools button isn't prominent, the current value of the time range option is completely hidden when it's on the default of "Any time", and the search query doesn't change if you alter the time range option. (And, to my knowledge, there's not a search query incantation for specifying the time range.)
If the current UI is a reflection of what PMs at Google want users to do, then they don't really care if the user uses, or even knows about, the option to filter by time. So I don't think it flies to point at the user and say, "you're holding it wrong".
And if the content isn't shared somewhere (typically on a non-Google property), then is it even relevant anymore? All the Googlers who defined search relevance outside of freshness have left to other opportunities.
