[CecilOne]

The problem always has been and always will be the "ordinary effort" factor. When the rule was new, I'm sure original rule writer(s) saw that as a conservative approach. They were so focused on infielder versus outfielder reach that they over-emphasized it and under-emphasized runner protection in the wording. The rule says infielder, not infield; because they considered them the ones that would make a play on the runner(s). Don't forget, all levels adopted the wording of the MLB rule and MLB infielders are better and faster than everyone else.
On a fly ball coming down right near 2nd base, the fielder might have to dash from a deep or shifted position. But a non-catch at that spot puts both runners in jeopardy if the rule is not applied. That's why I maintain that the rule should be applied with the intended runner protection superceding the fielder's effort. The "ordinary effort" applies to the landing spot allowing the fielder to retrieve a non-catch in time to put out the runner(s) on the force.