I read it a couple of years ago. I thought the entire last third was a disaster, including the endless "speech". The build-up was great, as the world continued to decline, and people were mysteriously disappearing. There was great imagery along the way. However, I thought the payoff at the end was laughable as Galt is revealed to be the man of Ayn Rand's dreams. By the time Galt makes his speech, every point of it has already been made by other people in the story. Leftists who believe leftist dogma would never accept the common sense espoused by John Galt. Maybe there was no way to wrap up the story in a neat bow as Rand attempted. I think it should have ended like 1984, with the future simply looking more dystopian.
I really liked the premise of the book, and found the the first two thirds to be quite gripping.
Your post summed up my take pretty much exactly.
The last part of the book also showed her stoicism almost as a religion. Galt was ready to chastise them if they were saving him for him, and not for their own selfish reasons. At least, that’s the way I remember it.