The problem here;
1.People on imageboards/textboards demand anonymity, so a forum/board has to have unlimited guest posting.
2.Anonymous posting invites spam and trolls that would ruin the forum easily, by mass posting random drivel.
3.Measures against that(captchas/long delays between posts) drive real posters away.
4.Maintaining forum without #3 is a pain the ass 24/7.
I like to sleep, have free time and not interrupt my life each few hours to "check how forum goes".
5.Enforcing usernames have few disadvantages:
it creates cliques and reputation-based posting, but its a lesser evil than unrestricted access, Unfortunately it drives away "Anonymous" type posters that only care about posting.
6.Enforcing pre-moderation of each post reduces interaction and drive people away, also doing it for more than 3-4 posts will be eventually required as trolls will post legit until fully approve their account for unlimited posting.
Its also extremely unscalable, when you have more >50-100 users, pre-moderation has to be delegated.
I tried some wiki sites, but they had zero interest from visitors and very low traffic, i'm slowly migrating(good) content to github, where i assume the site won't suddenly go away(MIcrosoft won't get bankrupt anytime soon), like wikidot hosting staff.