I beat the whole arcade mode on level 1 difficulty getting perfects every round and only earned 200 points. I put in my initials and this achievement didn't pop.
I put the difficulty to level 8 and saved scummed my way to winning 3 rounds with perfects and super move victories. I earned 700 points doing that, then lost the next match. After inputting my initials I then asked if I wanted to upload my score online.
I don't know if it's the high score or losing the match that prompted the request to upload, but winning one match on level 8 difficulty using the save states is way faster than beating the whole arcade mode.