Meta keywords are great for hypertext docs! They help humans find information by looking up keywords, an ability we developed over several centuries, perhaps starting with indexing commonbooks (see Locke's trestise on the subject).
Imagine two people telling you about keywords: a librarian and an SEO consultant.
One will tell you that knowledge can be structured for easy retrieval, and should therefore be prepared in a way that assists in future humans finding what they *need*.
The other will tell you it is a useless field of metadata, but if you insist on using it here are the ways to game "the system"...
My theory is that base capitalistic impulses make people build hypermedia docs in a way that is harmful to people in both the short and long term. Instead of reaching for our higher selves, we compete in hunger games where nourishment is increased distractability, until the players becomes the administrators and continue the cycle of distraction and "profits".
Be a librarian! Build your legacy, not on the bones of commercialism, which while seemingly immortal, will rot away, taking your culture with it. Build on community, with people you can connect with in other contexts aside from the overstimulated circus where everyone meets today.
Let's build cozy cafés and anarchist book shops on the web! Evacuate the corporate skyscrapers, they aren't up to standards, and your life is miserable each moment you spend there...
For folks that see capitalism as the best system among all alternatives, let me share a story of how I spent a summer hitting everything with a hammer, as it was the only tool I had. All my problems seemed to be solved, though everyone else's seemed to amplify.
I couldn't figure out why, though, because the one problem my hammer couldn't solve involved leeches. Some said leeches weren't the best solution, but what is the alternative?
When it comes to meta keywords and gaming search engines, a critical post-mortem might suggest instead of letting search engines "solve" the "problem" for us, we should have treated people like accountable adults, and exclude their corrupted knowledge from the personal searches.
Could it have been fixed? I don't know. But I do know that the solution was based on profiting while addressing a pain point, and that is fundamentally stupid stance to take for our species.