It's important to play nonmeta because sometimes the meta can get very boring, especially if you've used the same build over and over again for a few years, you might want to switch things up a bit just for the sake of it.

No, I'm not joking. I actually use this build and have gotten great results.

I can run up to almost anyone and pretty much 100/0 them right away.

I'm really serious, here are some match histories to prove that you can actually do well with this build. On average, over about 300 games in Season 5, I averaged 23.4 kills per game as Akali, including many games with this build. I was also at one point on a record list of most kills per game at #1 in the world. I think I might still be on there.

I have gotten I think 8 pentakills as Akali using all nonmeta builds.

Heimerdinger
Teemo
Tryndamere

Avoid these champions if they're on the enemy team:
-any tank with hard CC
-any mage with a stun that's also somewhat tanky

Champions to chase and get fed off of:
-almost any ADC, especially Ashe, Kog Maw, Miss Fortune, Varus
-non tanky mages like Zyra and Lux