Dear Riot: A question about the new group system

With you guys debuting the Group function this patch, there has been a lot of talk about the member limit on groups. While I do agree that there shouldn't be a cap on the amount of members in a group, I do recognize there may be something I am not seeing. So I am curious to know, what specific reason(s) do you have for putting a cap on group membership?

Thanks for your time- Yaso