It’s really not, if you watch the video.
It’s saying that, preferences, while subjective to individuals, can be far more objective with population group clustering.
Also, the reason I mention it is because the “fun is subjective” is a cop-out argument that implies that industry best practices to create fun, don’t exist. When they very much do exist.
For example:
Is Microsoft's takeover a good thing? - #95 by GreyFalcon-11737