Champ Select - Can someone explain this behavior to me?

You're in draft pick. You have your champ selected and ready to go as you wait through the bans and other picks. You don't talk to the other summoners (fine). Eventually it's your turn to pick - you have your champ selected and ready, all you need to do is lock it in.

And then you wait.

You wait until the very last second, then lock your champion in as the timer hits 0.

... Why? I'm not even mad about it or anything, it's just the most confusing thing in all of League because as far as I can tell there is no reason for it.