Nah, it's an awful way to learn. Especially to learn to be good or great.

When you start reading, it helps to have some guidance towards good and relevant books, from e.g. school, mentors, criticism, etc. Then, when you encounter a "bad" book, you have some benchmarks from which you can build your capacity for analysis and critique. (Testing your analysis and critique with others helps, too.)

If you start with "bad" books, your concept of quality and what's possible is constrained. (Like when teenage boys read Atlas Shrugged.)

Reading slop code is a terrible way to build a mental benchmark for what's good, what's possible, what's elegant, and writing good code that is respectful to your fellow human beings.