In grappling with this question myself -- it's a good question -- I've concluded the interest is in understanding and predicting the behavior of a system based on a few laws.

The system is quite complex and full of exotic objects, so ordinary real world intuition is a poor guide. And the laws are couched in a mathematical language that is also foreign to our everyday world.

Yet, predictions can be made and tested. It's an intellectual puzzle like "what does this very tight loop do?", or "how does the Y combinator work?" -- but in a different arena.