Huge Problem with Team Builder Summoner Icon Reward System

As it stands, you unlock the Teambuilder summoner icons by just playing 5 games. You have no incentive to win and as a result my teambuilder matches have had a huge influx of "idc, just need games for the icon" and people losing as fast as possible and surrendering to get said icons. It should take 5 wins to get the icon. I honestly thought needing wins was what it was going to be, how could Riot not see this coming? If you make something a grind, people are going to find the fastest way to complete said grind. 5 games isn't much, but at least make the player need to win them. Losing 5 games as a support should not give you a support icon.