Are people squatting on these domains, making them exorbitantly expensive? I could understand if IANA didn't want people to purchase single-letter domains to avoid scams (e.g. owner of e.com can scam people with googl.e.com). But so many of these domains are registered and available to purchase. Any guesses on the reason?

[0] https://nerology.substack.com/p/xcom-is-twitter-but-what-are-a-zcom