The thesis is: humans have a right to personal property; it should not be taken from them and they should not feel guilt over having it. I agree with the thesis, but I disagree with Rand's moralizing. And frankly, the book is quite cringy. It's way too long: it's over 1000 pages when the point could be made just as well in a couple hundred. Everything is overly dramatic--Rand has an obsession with facial expressions, and she tries to assign gravity to every moment, which makes none of the moments have gravity. It's overdone.
Here's the summary: Rand creates a world where private property is easy stolen by those with political clout and industrialists are demonized. The means of acquiring wealth shifts from producing goods and services to bribing the correct politician and cutting deals in fancy restaurants. Consequently, it becomes unprofitable to produce wealth since it will just be stolen. The industrialists give up and everything falls to pieces. The looters justify their actions by claiming to act for the common good.
Rand's characters are completely unbelievable. None of them act like normal humans. John Galt, for example, is more God than human. He's the most altruistic person ever, while claiming to be completely selfish. James Taggart is on the other end of the spectrum--he's complete scum yet no one realizes it. Some stuff makes no sense. Everyone in Galt's Valley is altruistic--they sell things for the cost of production without taking a profit. Actually greedy people would (this is still ethical) try to maximize profits by capturing consumer surplus.
Rand gets upset about dogmatic thinking and then introduces her own dogma. She claims that everyone should think for herself/himself, yet doesn't allow any nuance in her own philosophy. She implies that all forms of giving are evil: to use the word "give" is taboo in Galt's Valley. (By the way, people there say "give" plenty of times.) Yet Galt himself basically gives away his electricity when he could be charging a lot more for it. He only has to charge slightly less than any competitor to retain his monopoly. Also, he has a monopoly, and most people with monopolies tend to exploit them. The whole thing reminds me of James Madison's quote: "If men were angels, no government would be necessary." Galt sets up what resembles a socialist commune with only hand-picked, hardworking, altruistic people (no one is disabled, on one has children, everyone is in the top 99 percentile of their field) and then claims that laissez faire capitalism is a good idea. Any system of government would work with that group of people.
It's so strange that Rand feels the need to defend capitalism from some moralistic standpoint. Obviously, it's immoral to steal from people. Everyone agrees on that. Everyone dislikes corruption (except those who use it to their advantage, I guess). The book would have been much better spent by exploring the experience of people living in a capitalist society under different conditions. Instead, she tries to convince everyone to believe in capitalism as if it were some sort of religion. It works--we get it! That's why we use it.
It's a shame that she's so strangely a zealot, because she actually writes decent fiction--decent enough for me to read the first 900 pages, and enjoy most of it.
Edit:
After thinking about my experience reading the book, I feel that I need to add something positive to this review. I remember really enjoying the book up until the completion of the John Galt Line.
Rand's philosophy is empowering: we're accountable for our actions. One thing that has stuck with me is Midas Mulligan's heuristic for choosing creditors: he doesn't lend to people who talk about how badly they need the money; only to those who talk about what they'll do with it to make more.
I also like the book's focus on thinking for yourself. It's not necessary to believe what other people believe. There are so many beliefs that are incorrect and unhelpful, and so many opportunities to improve life. And I appreciate the book's humanistic philosophy: the mind is man's greatest tool, and we should use ours. I choose work that is mentally rigorous--it's rewarding, engaging, and high-leverage.