I'm guessing OP is caching results so only has to process each video once (which I would do as well). The limitation makes more sense when you consider % of cache hits with the limitation will be much higher, which means lower cost for running the free tier.
It makes sense though, because you might be the only one interested in a summary of those long-tail videos, whereas the cost of the summary of more popular videos can be amortized across many users.
Yes, the other guys above have already responded that this way I want to increase the likelihood of repetition. If you do the summary for free, at least there's a chance someone else will need it.
It's a hypothesis and on my current traffic I can't say it's worked. Maybe I'll change the limits when I have more data.
Video has less than 30K views Free plan is limited to videos less than 1 hour long and with more than 30k views
This is a very lame limitation in regards to views. Honestly trying to see if my videos were delivering enough value to justify the title.