So - I don't buy the mental/physical distinction. The only real difference is a mistake made early or later in the process. He could have fielded that as a single with ordinary effort - period. Whether he blew it by moving his leg wrong on his 1st step in the wrong direction and didn't get there, or by moving his wrist wrong at the last second for it to clank it off his glove, is still the same thing - it's still his brain that did not do the right thing with some part of his body in both cases, and it's still obvious that he failed to execute ordinary effort. If you take on the mantel of doing scoring then it's because you have the experience to draw that line. I think that play would have been pretty easy for instance. If you throw up you hands and say you can't judge ordinary effort unless it clanks off a guy's glove just fold up the process and quit scoring because that's such a trivial standard for mistakes that it's meaningless. After all, the actual point of the exercise to supposed to be to determine if a run was earned, so by rights the quality of the struck ball should also figure into it. That would be the key to making a judgment on that play, not only what the fielder did/didn't do, but that that ball was hit in such a way that it only merited one base given a competent fielder.
That said, it's purely an aesthetic argument. Scoring doesn't make any difference to anything in the game play so in the end nothing is affected by anything the scorer does, and as long as scoring is fairly uniform on team's player's stat are not dis- or ad-vantaged. And good modern stats bypass. scoring. I remember the Tigers we actually one of the last parks that kept scoring tougher when things where shifting and I imagine they got pushback from the team about it. But it's good fan grist.