If you want to go to a forum that is free of censorship and free of strict rules that limit your ability to rank up, then sign up in Roger Ver's forum,
https://forum.bitcoin.com/.
people complain about merits because it slows them down and makes it harder to rank up
they want to rank up because higher rank enables them to join a signature campaign with higher payment
and I think popular is not the correct term, but
"another potential forum" should be more appropriate
as you said, even if they have... those sig camps probably not as succesful as those in bitcointalk.org
thus it limits the budget of sig campaign to pay better/equal payment to those in this forum
and discourages users to join the forum because their intention is not for the discussion but for the money in the sig campaign