While I agree with the Steel Wind Strike being an insult to put on a wizard and none of the martial classes, this is a bad argument because pretty much every anime swordsman who would pull out a shit like Steel Wind Strike as it is written, is explicit supernatural. I get your sentiment but this is a very flawed, easy to dismantle argument.
If a warrior can withstand the tail weapon of an adult dragon without batting an eye, they should be able to perform Steel Wind Strike just fine.
Besides, nothing in SWS is explicitly supernatural, except for the “teleport next to one of the targets” bit, which could be flavoured as “you move really fast next to them”.
That’s why I’ve said “as written”. I’m sure this was designed by people who hold the mindsets that doesn’t do reflavoring (the recent feat allowing you use deck of cards as spellcasting focus from Book of Many Things is another good example) and also thinks Fighter and Barbarian and Monk are just “guys at the gym”. Sadly same sentiments were in WotC since 3rd edition, hence why options martial should get were all given cringy anime names and relegated to new classes and explicit called magic by the text.
