There are enough merit sources and merits in circulation for a fair distribution of merit. More merits in circulation would mean more merits in the hands of merit abusers which isn't something we would want to see happening around, do we?
Not true, the merit abusers or spammers are not going to get merits at all as merit sources will never spam spam posts. So, it will be the good posters who will be rewarded if there are more merits in circulation.
Do you mean that the good posters will be rewarded more if there are more merits in circulation ?
I think that theymos and the mods know how many merits to send to each merit source and they are the better judge to see if these merits fulfill the requirements. Also, we should also know that it is not only the merit source who can distribute merits, also every receiver can send one merit when he gets 2 merits, so this also has to be taken into account when allocating merits to the merit sources.
So, for example if a merit source has 1000 smerits to send at his disposal, technically it is 1500 merits that can be distributed.