"As to why successful people don't read more difficult books, well, being a great mathematician just isn't that important to success."
???
"Rudin is like reading the source code"
Rudin's book is incomplete to a beginner. The analogy doesn't work at all.
Your argument is that Rudin is hard for incidental reasons: he skips steps in his proofs. I personally did not feel this way when I read the book. But I am open to the idea that Rudin is imperfect. I personally admire Rudin's concision, but that may just be my personal aesthetic preference.
My point, and perhaps I did not convey it well, is simply that some subjects (in particular mathematics!) are inherently difficult. And if you want to learn them well, you have to face that difficult head on: you have to read hard books. Euclid's old saying comes to mind: "there is no royal road to mathematics!"
"Your argument is that Rudin is hard for incidental reasons: he skips steps in his proofs. I personally did not feel this way when I read the book. But I am open to the idea that Rudin is imperfect. I personally admire Rudin's concision, but that may just be my personal aesthetic preference."
Good god.
The programmers here may appreciate this analogy: reading Rudin is like reading the source code, whereas more gentle texts read more like documentation or UML. That's not to say good doc can't be enlightening, but in the end only the source code matters. The doc can be wrong, or misleading, or incomplete. If you want to really understand what's going on, you need to read the source. It's the same way in mathematics.