I agree with your advice to "Descend the rabbit holes!" but feel it needs a little more context. The real question here is not 'should I descend rabbit holes?' but rather how often or when.
If you are building something, you inevitably spend some part of your time writing code that is familiar and boring (let's call this WORK), and part of your time exploring unfamiliar code and concepts (RABBIT HOLES).
Going down rabbit holes is not work, it is a form of learning - in fact, in the world of software development it is the best form of learning because you have a highly relevant problem and supreme motivation to solve it.
At the end of the day, however, going down a rabbit hole is no different than reading a book, or articles on HN. It is not actually work, and fooling yourself otherwise leads to the blurring of what is work and what is learning.
You should always be learning, as much as you can. But you must be honest with yourself, there is probably more work to be done, and you can't possibly get on with it until you pull yourself out of the rabbit hole.