The later you pick your champion, the more responsibility you have.

You have a responsibility to make sure that there is a balance in damage types, that there is a balance of tankiness and damage, that there is synergy between what you pick and what has already been picked.

I'm so sick of locking in a champion, making myself a coffee, and coming back to my computer and wondering wtf my team comp is.

At least have versatility in your playstyle so that when you pick Blitzcrank instead of a peeling tank you know to stand away from your carries and pull the enemy frontliners off them instead of standing on your carry's head and pulling the enemy Darius right on top of them.