Accounts with a lot of Merit can make alts and make push them over the minimum requirement real fast, basically abusing the system.
The participation of alt-accounts is generally prohibited in most (if not all) campaigns. Also, it would be quite noticeable if an account gets 250 merits from another account (not to mention that you have to have 500 sMerit first if you are not a merit source) which would ring the bells of our forum police almost instantly.
So I think this scenario would be negligible, but at the same time rewards those posters who post very good posts from the beginning but are not registered long enough to reach the "Legendary" status, for example.
And let's be honest: the rank in the forum says 0 about the quality but is rather to be seen as a reward for forum loyalty.
@icopressBut what could definitely be an issue is that the signatures of Legendary members are much more extensive and therefore much more noticeable ... that directly affects the advertising value of the respective postings as well.