Hi Nathaniel (or is it Nathan?),
I remember watching that video, but the only thing that stuck was that example about the culture not having enough food and distracting half the population with playing games. I did not rewatch it, so anything I say may be off-topic rambling.
I don't think it is a problem per se that not enough people play games, as it does not interest everybody. Likewise, I don't consider it a problem that not all people play musical instruments or read books or whatnot.
However, I do think that the gamification can increase individual productivity. It's very tricky to turn a chore into a fun game, as can be seen by most of those failed games targeted at children to get them to learn basic maths or somesuch. The key ingredient is the fun, in my opinion: First you need to have a fun game or activity and then you can sneak the education or other benefit in there. Strange enough collecting stuff seems to work well, so achievement hunting is a "good" mechanism for gamification. I learned (normally I would write "learnt", as I am unfortunately using this weird mix of American and British spelling) English by playing computer games (the old Sierra adventures), watching cartoons (80s style Transformers) and reading fantasy books (Dragonlance) as a kid, because it was fun and not because it was on a curriculum. Those media weren't specifically designed to teach English, but they were interesting, so picking up the language was an unexpected bonus.
I am of the opinion that gamification, education through games and improving the world via gaming needs to prioritize creating a fun user experience and offering the actual goal as a secondary benefit. Usually it is tried the other way around, dooming the whole project to failure.
All the best,