Ashe has greater strength's than Kalista's.
Hawkshot is global, can't be interrupted, has standardized champion vision and other things.
Sentinel is much less reliable than Hawkshot. It has a slow travel time, cannot travel through walls, gives situational vision, isn't global, and gives gold to whoever finds it.
Ashe also has a global engage/snipe tool which allows her to save allies, make a pick, disengag, reengage and deals damage, all on an 80 second cooldown which can be reduced by cooldown reduction, which NEWSFLASH, most Ashes build due to Essence Reaver,
Meanwhile, Kalista has a Zhonya's for her support; which is not global, can't be used unless her support is within two auto attack ranges, does no damage, and has a delay. oh yes, but it's an AoE knockup.
Ashe has better base stats, synergizes better with AD and AS items, better early laning, better late game, and better utility. The only thing that Kalista has going for her is that she can dash between every auto attack.
Ashe can kite bruisers almost as well as Kalista; Frost Shot gives her a lot of utility in terms of chasing and kiting. Though versus Assassins; Kalista can kite a little better than Ashe; of course Enchanted Crystal Arrow can hard cc Assassins fairly reliably. whereas Fate's Call has a delay.
Remove that passive, and why would I pick Kalista over Ashe? Sentinel does practically 0 damage now in lane.