Solid article. Funny how the player base considers carries as pure auto-attack based champions while the term 'AP carry' exists.
However, I would argue that:
Additionally having some ranged poke works wonders for the viability of melee carries.
isn't merely good, it's broken when said poke can clear waves. Kha'Zix and Zed are too safe; while you could argue ranged ADC are just as safe, these don't have the sheer roaming and dueling power of assassins.
You can't really prevent Kha'Zix and Zed from farming, you can't gank them either. You merely watch them farm and roam a bit until they ruin your day.