Hornpipes also come in 3/2.

To my mind it's not just the time signature that defines what it is but also the way it's played. An Italian Tarantella or Quadriglia are both in 6/8 and sound totally different from a Jig and polkas are in 4/4 but can sound rather different. I haven't got the skills (language or musical) to adequately discribe the differences but they're definitely there.