maybe these rules are for the goal of eliminating newbies from the way and as you said the reward will become bigger
Eliminating the newbies? I'm pretty sure Theymos prefers to have new users registering in his forum. It's just that the new registered users were increasing(both from legitimate users and from account farmers), while the post quality was dropping due to the obvious spamming from people that are ranking up their accounts.
Yeah, I personally think it's more about eliminating the non-contributing newbies from the forum.
Word goes around quickly that you won't get into a campaign when you're full-on spamming the forum.
Plus, perhaps more and more newbies try to contribute more with the new merit requirements.