I see the logic, but in my opinion fumbles with this shortcut are catastrophic enough (sitting there waiting for N files to open in however many apps so they can all be closed) that the “logical” option shouldn’t necessarily be favored. That said, the alternative doesn’t necessarily have to be Command-O (though I like the mnemonics of that), some other modifier paired with return/enter could work too, but I really don’t think it should be a single key shortcut.