Why are there soooo many left handed champions in this game?! Seriously, I know I'm not the first to notice it...Pantheon is an example...he is left handed....(he would never have been a spartan because of that..unless he is ambidextrous. Ashe too, and kayle...lots of others. why rito!? who there is left handed?
It just seemed right.
"You are wonderful!"
"I thankee"
"I admit you are better than i am>"
"Yarr, then why ye be havin a worm-eatin grin?"
"Because i know something you do not know!"
"Yarrharr?"
"I am not left-handed!"
My guess is its just an aesthetics thing... ie the champions just look better or whatever during their animations that way. If you look at pantheons splash art 2 of them he has his spear in his right hand. And he isnt a spartan despite his armor, he is Rakkor a Riot made up tribe, so Spartan references only go so far before its irrelevant.
its because the world is made for right handed people and we need representation, and making a majority of the champs lefties makes us feel included ya damn righty.
The real question is why does it matter?
I suspect there are sinister motives at work.
But Pantheon isn't and never was/will be a spartan because he's a Rakkor. While losely based upon Spartans it's hard to say whether they make shield walls or any other such stuff. And I'm betting that sometime in the future when they flesh out the Rakkor more they will be even more divergent from Sparta. I totally wouldn't put it past Pantheon to be ambidexterity as well.
Also Runeterra doesn't necessarily have the same conventions as Earth. So it could be that left-handedness is simply more prevalent there.
I don't think Pantheon holding the spear in his left hand makes him left handed. From what I remember of this sort of stuff the shield is generally held in the dominant hand because it's larger and heavier, requiring more strength to hold.
Left hand. Hmph. Stronger. Hmph. RIGHT ARM. 
Has anyone actually counted the amount of left-handed versus right-handed champions and compared that to a real-world number? I mean, so many champions. Surely many must be righties.
At least for Kalista, I'm assuming that it was (for future skins as well) to help distinguish her visually from Nidalee (who's right handed). For example, base Kalista and Headhunter Nidalee have somewhat similar color palettes. It's probably not the biggest visual difference that could have been made, but it could help in a minor way.
As Emofratparty pointed out, Ashe could very well be ambidextrous.
Varus is ambidextrous
Ambidextrous master race unite!
It's interesting to note that the in game models are left handed for the champions you mentioned, but the splash art doesn't reflect that.
Because Riot Reinboom has not won a match on blue side of the map since League launched. Developing a personal vendetta against blue-side, he forced the champion concept people to make every champion left-handed so their most awesome/dangerous side could only be seen when fighting from Red side. And now he can relish in the destruction of his enemies on the Blue side as he man-drops them to death from the most awesome visual angle possible.
And that is how left-handed baby champions are born.
That's very funny. I hadn't noticed. You are very observant. I will have to pay more attention to those interesting details.
