I thought this superficial kind of learning was more due to the necessity of being brief than the conviction that it's the best way to learn about a topic. We really don't have enough time in our lives to acquire an in-depth understanding of very many things.

You can trade learning more things superficially with learning fewer things in but in greater detail, but if you don't want to make a career out of your knowledge (where specialization is best) it seems like either way is fine if you just do it for fun. (Though I agree that specialization probably is more intellectually fulfilling that fact collecting.)