Could we not have just chosen which quest path we wanted to take?

I'm trying to go for the Nice path because I don't particularly like the look of the Draven gingerbread man, but having to do ARAM / LoTPK (or whatever the shortened form is) instead of summoners rift for the quest is... frustrating to say the least.

I'd have liked it if we'd have been able to choose which path we want to go down without having to complete one of the quests first as I would like to play some other game mode while trying to win the games I need for my quest without threat of going down a different tree

I really hope I explained this so it's understandable at the least, it's pretty early for me.