There's just not much purpose to clans at the moment - adding requirements for clan creation won't really change much imo.
Players who make clans for their own usually don't really want to get the "real clan" experience - if there was a requirement they'd just play solo as a lot of people did before the removal of clan creation paywall and forum thread requirement.

Keep in mind there are also no activity or alt checks done for unofficial clans - even if we were to require 2 or 3 people in order to make a new clan, this wouldn't really guarantee new clans' quality.