However, there are still loopholes for such members. For example, I often come across accounts that have either very little or no merit at all earned over the life of this system. But they continue to take part in signature campaigns because they have reached a certain level before the new rules were introduced. They live normally even as a full member, not to mention those who have been seniors and heros before merits were born.
The altcoin campaigns have always been lower quality. You'll rarely see users participating in Bitcoin signature campaigns without actually being a decent poster. The altcoins section is a different story, mainly because they're paying you next to nothing, because they pay you with their worthless tokens, which can't be sold regardless. So, naturally only lower quality posters are interested in joining.
However, if their posting quality is that bad you can report them, and they'll likely get handled.
Yes, I don't think those ranked up users prior to the merit system have any benefit because none of the bitcoin signature campaigns will accept you if you do not possess a good amount of merits in the last 120 days. Those not so good ranked up members have to work more harder in bounties and at the end of the day may get worthless tokens. Also the good thing about bitcoin signature campaigns is that almost all of them are being run by reputed members and they accept only quality posters.