(guaranteed) Threat range is huge when he has his ult, Q is a fairly big hitbox, and does a lot of damage with a lot of CC. His damage is actually pretty surprising, but then... tanks do that much nowadays.
Fuck Ezreal. Range and mobility are the worst things for a melee main.
If you ever trade with this guy after level 6, he'll call it an all in and run at you until you finally make it out of range. He can miss his snare and crow, use the DoT thing and ult you and you'll be outtraded. Champions without a cooldown to abuse are fucking annoying. It's just - can I kill him with my R? Yes: Kill him. No: Turtle. If R is down, what do? Wait for R to come back up. Then go back to question 1.