How can you not like a book with a title like that?
The Moon is a Harsh Mistress is considered a sci-fi classic, and Heinlein is often credited with bringing accurate science to science fiction. I was looking forward to this one; the premise focuses around a moon colony and its desire for independence from Earth.
One of the reasons I enjoy sci-fi so much is that, when done right, it's layered: a book about interstellar travel is really a commentary on individuality; a short story on a sentient computer has more to say about human nature than engineering. Good fiction works on both levels, entertaining but still having something important to say. It's why I love writers like Bradbury and Nagamatsu. The Left Hand of Darkness is a great example of the power that comes with mixing imagination and critique.
But some work is really just political commentary wrapped in a sci-fi shroud. It's why I love Asimov's short stories but had a hard time plowing through the Foundation series; when we talk about the future, intergalactic trade doesn't seem like the most riveting detail we can focus on. Or take Blake's Clean Air; it's an amazing take on motherhood, but the futuristic setting acts only as a greyscale backdrop. The Moon fell into the same pitfall: if the dialog had happened Earthside instead of on Luna, not much of the book would have to change.
It's a difficult balance to strike, and once I realised that the pendulum was swinging one way, my eye searched for more faults. The main female character, who was the first to take concrete steps towards revolution, is used as a vessel for correcting wrong ideas (No, darling, let me simplify it for you) and for praising the virtues of beauty. The moments of biggest change are brushed over, while random discussions get multiple pages. And the somewhat-alive computer could have been explored more deeply.
Not all sci-fi can be winners. Read other reviews; some people love it, others hate it. For me, there's so much good writing out there that this felt like a waste of time.