It’s not really an obligation for Merit Sources, but rather a responsibility which is time consuming at times. Nevertheless, Merit Source allocation may be adjusted at some point (by @Theymos), as it seemed to have been done a few months ago, making a better alignment between allocation and awarding history (upping some and possibly lowering others).

The average user should also try to award merits and not hoard them. After all, the system would be way better in my opinion if it were to be less Merit Source dependent and more of a general forum member thing.
Here though the average person will not really have many sMerits to go by (not including in this comment all the allocated undistributed airdropped sMerits), and may treasure them at times in a quid pro quo kind of scenario.