Kha'Zix is ridiculous when ahead

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1795046103/50086536?tab=overview

I got RIDICULOUSLY ahead that game. To put in perspective, for a good portion of the game I had more kills than the entire enemy team (at one point I had 10 kills when they had 9 collectively).

Why is it that Kha'Zix has to be so weak early game, when he can do this late game. He is a monster in comps where the enemy has to scatter.

Next time your team has etc. pick Kha'Zix and witness hell. Because they either group adn get fucked by AoE, or don't and get fucked by Kha'Zix.