Why is there a level bar on Team Builder?

I can understand a low level bar (Level 10) but seriously...Level 25? Team builder was made for 2 reasons:

1. To play with all of your friends 2)To allow players to tactically and strategically come up with a good team composition.

But why is there a bar now? What is this even solving? I say remove the bar or at least lower the limit significantly. This blocks off a lot of players that may be lower levels that want to either play with higher level friends or lower level players that do try to win.