Custom Summoner Icons?

I never understood why Riot never put in the option to use a custom summoner icon to the game, rather than buying a bunch of already-made ones for 250 RP.

Riot could simply do this:

1: You can purchase a "custom icon" from the Store for 400 RP. (More than other icons, less than a ward)

2: Once you purchase the "custom icon", you are allowed to upload an image of your choosing (.jpg, .jpeg, and .png format only) to use as your in-game summoner icon, as long as it's 128 x 128 pixels. (Note that once you buy the custom icon, you can upload as many images as you'd like)

3: Once you have selected the summoner icon you'd like to use, it will become disabled for 1-2 days so Riot can approve it. (No pornographic, gory, or inappropriate icons allowed)

4a: If your icon gets approved, you are allowed to use it as much as you'd like. On the offchance you stop using the icon, you don't have to re-send it for approval if you're going to use it again in the future.

4b: If your icon gets denied, you (obviously) cannot use that icon, as it was deemed "inappropriate". You can still submit other icons for approval.

Thoughts?