What they do is they mirror each other, usually you'll see 2v1 top/bot and the junglers coming in to join at around the same time making it a 3v1, this way they both get the same rewards without taking any risks. Having your mid lane running around the map at level 1-3 is a huge gamble...
What this means is teams pretty much just skip the laning phase and go straight to mid game. This can make for some pretty fast paced games and can be entertaining to watch but Riot doesn't want it to be a must-use tactic.
Your opinion.