Merit should be the qualification or aptitude test to show that you're qualified to earn via posting since campaign managers can't be trusted to hold some sort of minimum standards, and this 'qualification' should be much higher than one merit.
Should be but it is not. It could be called this aptitude test if all posters got reset to lower ranks and had to earn merit to advance. Since higher ranks got a lot of merit for nothing, same as old, abandoned accounts, that were later traded and used as merit donors, the system is not perfect. At least it does not act as an equal test for all members.
I agree with the rest of your post and believe that having this anti-spam measure is better than nothing, but in terms of equality it is lacking.