Is it necessary that there be some human logic to it, just because the Sages decided to interpret the verse that way? Instead of interpreting “and a stack of grain or standing grain is consumed” as referring only to visible things, they could have interpreted it as only produce of the soil (without any logic), or only something immovable (with the logic that it can’t be whisked away).

Or maybe there doesn’t need to be actual human logic in the hidden-property exemption; rather, from among all the interpretive possibilities of what is unlike standing grain and a stack, hidden property is simply the least illogical option.

There is supposed to be logic in textual interpretations, since the Sages decided to interpret it specifically this way. True, sometimes it will be whatever is the least implausible among the options, because there is some trigger that forces us into an interpretation.