On Calvinism God makes some people (the elect) “smarter” (or insightful, or able to understand truth), more humble and privileged by a work of irresistible regenerative grace. So, on Calvinism those who believe really are “better” or “more capable,” which is why they can believe the gospel and the rest cannot believe it (for reasons beyond their control). Granted, on Calvinism, this regenerative grace is given unconditionally and it is not in anyway merited by the elect, but that does not change the fact that upon being regenerated the elect are made “better” (more capable, with a new and better nature/heart) than their unbelieving counterpart.
On Provisionism (Traditionalism), all people have the necessary insight and moral capacity to respond willingly to God’s appeal. Thus, all are truly “without excuse” because everyone has everything they need to believe in God. This is due to the fact that everyone is created as His image bearers in a world where His truth is made abundantly clear and believable (Rom 1). On Provisionism, no one can fall back on the excuse that God did not make them morally capable to respond positively to His own appeals or insightful enough to understand and accept plainly spoken truth, like they can on Calvinism. On Provisionism, the Fall doesn’t cause humanity to become morally incapable of accepting God’s appeals to be reconciled from that Fall. We do not believe that has ever been established biblically.
This Calvinistic argument may sound pious because it’s attempting to give all credit to God for all the good things, but in so doing it also inadvertently gives God all the blame for the bad and removes any real semblance of human responsibility for unbelief.