I sometimes go through my Youtube history erasing from my history videos that I watched years ago because Youtube keeps suggesting things in which I am no longer interested.
However, cake lets you manually adjust and edit your interests.
The problem on Cake is probably going to be what is called "Controlled Vocabulary".
What often happens when metadata is assigned is that different people use different words for the same thing. A controlled (or limited) vocabulary attempts to prevent there being multiple tags for a single concept and also what are called false positives when one word has multiple meanings.
Photographers and Journalists often use the IPTC system, while Libraries also have controlled vocabulary systems.
Because Cake is still small, this problem has not become major yet, but it is likely to grow and transpire.