His ult isn't even as strong as Ashe's, because the stun opens up so many possibilities. I don't know why you'd bring it up. Ezreal's attack speed debuff also is significantly less than Graves self buff, so again, I don't know why you are bringing this up. 70% is more than 40%, last I checked. This is one of the reasons Graves is often used as a counterpick to Ezreal.He has a better escape then Corki and Graves (considering it can be used to escape Blitzcrank grabs). His Q has a ridiculously long range. His attack speed passive coupled with his attack speed debuff (which also buffs allies) easily beats any attack speed Grave's gains from his E.
His ultimate allows him to have presence anywhere like Ashe. However, the damage potential for his ultimate is much higher than Ashe's ultimate. Furthermore, he can use his ultimate to clear minions that are pushed to a far tower (unlike Ashe). This can allow his team to keep pressure in one lane since one of the enemy players might have to leave to respond to a large minion wave or risk losing a different tower.
Someone like Draven will just out-trade Ezreal in almost every scenario. Being afraid of Ezreal is ridiculous when he's a fairly standard AD carry. There are much more dangerous champions you can ban out. Like let's say you ban him. Oooooh no they have to pick Corki or something.