The system hasn't been updated since it was implemented, right? I don't think I've missed some kind of an announcement.
Shouldn't the team try and make the system better? Do they believe they launched a perfect system by day one?

I for example find it harder as time goes by to know if a "Full Member" with 101 merits have worked from Newbie with 0 merits to 101, from "Member" with 10 free merits they got 91 or if they was already a "Full Member" when the system launched and they only got 1 merit.

I believe this is more important to signature campaign managers who want to filter the users than anyone else, but still, it'd be helpful to know how many were free merits and how many acquired merits.
Ofcourse you can check the date the user was registered, but as I said this gets harder as time passes and it won't be easy to remember or to calculate how many free merits someone has based on the date they registered.

And also, it's not that hard to split that info into "Total Merit" and "Received Merit" or "Community Merit".