Forum users have right to keep their sMerits. There are no point to do that, but you simply can't force users to spend their sMerits.
And it's not only problem of low ranked members. There are thousands of higher ranked members who haven't even spent any of their airdropped sMerits, despite that more than a year passed since release of Merit system. And then people are complaining that's difficult to get erit, merit sources aren't giving out enough merits and etc.
As a high ranked member, I also blame myself for not giving out enough sMerits. Sometimes I just too lazy to do that, I know, it's bad. Now I have more than enough sMerits available, I should spend it more actively...