"Generally, if you're writing long, rambling posts, there's a good chance that your understanding of the subject that you're writing about is sloppy "
I don't think that's true. Understanding something and being able to write about it are two different things. It's a good thing to learn to be concise though.
Good writing is often a very small subset of a topic. If you are an expert on a topic it can be very hard to omit a lot of detail you may find important but will just overload people.
Toastmasters taught me a lot about this. A lot of my speeches were 15 minutes long at first. Cutting them down to 5 minutes was very painful but it definitely made them way better
I don't think that's true. Understanding something and being able to write about it are two different things. It's a good thing to learn to be concise though.
Good writing is often a very small subset of a topic. If you are an expert on a topic it can be very hard to omit a lot of detail you may find important but will just overload people.
Toastmasters taught me a lot about this. A lot of my speeches were 15 minutes long at first. Cutting them down to 5 minutes was very painful but it definitely made them way better