Atlas Shrugged was "OK" if one skips over the long speechifying.
If you do that, you miss all the philosophical underpinning of the novel. At that point, you've read ~1100 pages and all you have are shittily-developed cardboard cutout characters and the basic idea of producers and moochers/looters without the understanding behind it.
Rand's problem is that as she got older, her books got longer, and longer, and longer... But not better.
Anthem was a good and short book. Lighter on philosophy but an easier read.
The Fountainhead was starting to get long, but it seemed like the character interplay was better, and she at least seemed to get to the point.
Atlas was just... A tome. The sort of thing that as a writer she thought "this is going to be THE book that I get to put EVERYTHING in--the magnum opus." And then the actual writing quality ended up IMHO being secondary to the message.
Heinlein was different. He was certainly more in the libertarian mindset as a writer, and that [and the philosophy behind it] came through in his books. But he could actually
write. The philosophy underpinned the work, instead of the work being a vehicle for the philosophy.
Well he also killed a couple of folks just to see if he could get away with it, so it's possible that he was unrelatable for me, for that reason...

Well, there's
that.