Such people are the real hoarders. Are they not reading any posts? If possible, such like them should be penalised one way or another to force them to at least share merits as it's also important to the forum to make the good and deserving users feel appreciated and known. Besides, I always appreciate those merit sources who dedicated their time to creating threads to view the unmerited posts that deserved it. But more is needed to make it effective even as some of those links above are no more effective.
There is no point in hoarding the merits
There is no point in hoarding sMerit; keeping it yourself does not benefit you, and we reserve the right to decay unused sMerit in the future.
But it's up to them whether they want to send it to anyone or they want to let it decayed if that ever happened and I don't think penalizing them is not the right way either. Usually members send merits to worthy posts but it's very rare to find people who is not sending any merits at all and probable reasons are they are not interested in reading other replies or they set the standard too high that can never be met.