Take your pick then, prospects of less security and shrinking market share with a 'comforting' cap hoping for a better value gain, or a more realistic scarcity model with better long term security?
My pick is always the more realistic scarcity model, like that of Decrits or eMunie for example, where supply adjusts to demand proportionately, not inversely proportionate like that of Primecoin.
Your argument of Primecoin being scarce is only true based on the
assumption that demand for Primecoin is on a
constant linear increase. And as we have seen so far, this is not the case, because I have been observing demand for it closely since the begining.
But when that demands weakens, the opposite is true, Primecoin's security not only quickly weakens, it's value is also quickly lost, due to the new unnecessary rising inflation from difficulty drop, resulting in faster XPM production rate.
So in fact, Primecoin is the prospect for less security and shrinking market share without the 'comforting' cap to even gain better value and unrealistic scarcity model without any guarantee for long term security.