Earlier quoted context omitted.
Adding a barrier of entry to something generally improves the quality of whatever it is.
At the cost of quantity, but agreed. (There have been some really interesting displays of this, like Robot 9k avoiding chat spam, or Kingdom of Loathing's 3-question "test" for joining global chat.) Print fiction stories are higher average quality than web-published or fan-fiction, because they costs money to produce. Nobody prints and binds 500 words of unfinished, unedited rambling, but they certainly put it on AO3…
A lot of people do. They just don’t reach you (vs internet distribution).