For once(!!!!!) I agree with you. One of the surprising disappointments in BsAs milongas so far, is the wish of the porteñas to step only on the one in Vals with no change in tempo at all. The more known milongueros varied their tempo so I have no explanation other than it must be what some dancers are used to. Similarly in tango, no quick steps even if the music moves me to dance some. This is less of an issue to me than a strict tempo Vals.