"/tick rate" command is inconsistent (can slow down player movement but can't speed it up)

The new "/tick rate" command is incredibly confusing.

Why does the "/tick rate" command slows down the player movement when the "/tick rate" is below 20, but doesn't speed up the player movement when it is above 20?

It is inconsistent and doesn't make sense. Why not add a separate command for player tick rate by adding a "/tick player" command so the "/tick rate" command only affects non-player mobs? It would make more sense and not make the "/tick rate" command inconsistent & confusing.