ADC mains are not a patient bunch overall. Her kit is just underestimated because she's not the most obnoxious bot lane.
Ashe is mostly passive in lane while she farms and looks for openings created by her support or the enemy. She's a rather safe pick, but I see people play her so aggressively. An aggressive playstyle on Ashe rarely works. A good Ashe is patient and waits for an opening.
People severely underestimate how deadly her passive and Ranger's Focus stacks are. If she catches you out of position, then you're pretty much dead unless your support is Soraka. That moment of her turning to eliminate an out of position player is always shocking to see, because until then the most active in lane she gets is when she sends out Volley.
One thing that drives me crazy as a support main is when people don't use her Hawkshot enough. It's an extra form of security when you think the jungler or mid laner is coming to gank. That extended vision is invaluable at all portions of the game. That ability has got to be the most underused in the game though.