For example, couldn't Notch post on Reddit every day, incorporating changes/suggestions/criticisms people would fling at him anonymously and randomly?
Is there something about 4chan/8chan that is intrinsically better for building Minecraft that isn't available anywhere else?
I'm convinced the initial randomness/anonymous feedback/chaos of that initial period helped grow the spark from the ember that split off of Infiniminer.
There is something creative in the chaos of 4chan - just look a greentexts. 99% of them are absolutely terrible. But the occasional gem catches on and made viral on the larger, less vile sites.
Also, I can't believe I forgot about Caturday. That started on 4chan as well. (also 10+ years ago).