Why restrict a cast of characters that are randomly selected anyway?

I just want to play a game with different champs. Diversity is the thing that makes me play league. i enjoy going into a game and seeing different champions. this snowdown arurf doesnt feel liket that. theres always a trynd or a shaco or a jax. this is less fun than ascension. why can't we have 10 ban urf and choose our own champions ? im already bored of new urf, and it seems to get worse every time its brought back