AD vs AP diversity
You are 10x more likely to need an Ap last pick than an Ad... how is that diverse?
Don't tell me, "oh if you are Ad heavy you can pick this MM or that support for supplemental magic".... this is about 100x easier said than done..
Everyone has experienced the ample stubborn people who play whatever they want even if it guaranties the enemy's will rush thornmails, hearts, omens, hourglasses...
Even if they tried, there is like no viable jungle mages, supports usually don't get nearly enough gold to be considered a carry, and marksmen like corki/kogmaw are still only dealing 50% magic
There should be more pure magic marksmen that do not require thousands of mana to sustain damage, and I have no idea how you can balance jungle mages but get that ish done..