If one can't see an attacker from four or five feet away, he needs a good pair of glasses. Could make sense at a non-combat distance like fifty feet away, but kata wasn't designed for that. But if you do drop down, by the time you get up the attacker could have moved, and you'd have to do it again - all that going up and down would be tiring and give my aging knees too much of a workout

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I never saw a moon so bright it could blind you. This makes more sense in a DAY time situation, not night. More likely they are parries and low strike or block. If it was to shield from moonlight, it would only be useful on a full moon night without clouds or at the right angle or time of night. Application would be limited.
Many of those linear front-to-back pivots are to facilitate throws and not to fit combat into a narrow space. Besides, wouldn't it make more sense to throw the guy OVER the bridge (or into a wall) rather than just back on the line of attack?
Regardless of the stories, my view is that everything in kata is a direct combat technique. This seems more logical and practical than the interpretations in question. Remember,
oyo was still guarded in the 50's and 60's by the Okinawans and not revealed to short term students (especially foreigners like American military) and so other explanations were given for some bunkai. Even a punch can be done at night - that doesn't mean it was
designed for it. (I'm trying hard here to make you a believer

but I know it's hard to abandon what one was taught.)