To be fair, the power was added as a failsafe to be used for legitimate clemency in cases of judicial overreach which is also a concern. I do believe it was added with good intentions.
But like many aspects of US federal government, the people who drafted the rules naively presumed the people invoking them would have some level of integrity and a shame response that would stop them from using it for openly corrupt purposes.
They were, of course, wrong.
At the very least they should have ignored Hamilton and made it so that Senate approval was required for the pardons... though even that wouldn't be enough of a check today because we now know that Congress is capable of completely abdicating its power to the executive branch.