There is no doubt the merit system is more in favor of old members. Now they are benefiting because they knew the forum earlier.  I expect this to be finally changed (I don't think it happens in near future). I don't think 5 years later, some users have a special privilege only because they registered earlier. Theymos will decide. All airdropped merits may be removed in a second, they might be decayed over a year or there will be a complicated formula.

Anyway, now thanks to signature campaign managers, there isn't a big problem. A legendary member who hasn't earn any merit is not qualified for participating in a good signature campaign while there are users with member and full member ranks that are participating in good campaigns.  There are many legendary members that are wasting their time in altcoin bounties without any income. Now having an account with a higher rank doesn't increase your chance of participating in campaigns.