Because if not then all the rank will back to newbie so it's given for free, don't forget Legendary members gets 1000 merit don't know how much sMerit they got from system.
Accounts created after 2018 do not receive any privileges from the forum, and therefore all merit becomes more valuable.
But if you look closely, today there are a lot of people who very quickly increase their rank and become legends by giving their devotion to the forum.
Therefore, it is in no way worth relating to the issue of what it used to be just to increase one's rank than it is now.