basically I have no idea why you are upset. last season near the end of it, when I was newer to this game even I was able to identify how cheesy and broken Zilean was. His Q's had ZERO counterplay in lane and especially later in the game. You could legit just run full pen or ap runes, wait a few levels to get some base damage in your Q and then just walk up to ADC, double bomb them walk away. rinse repeat until forced out of lane or dead.
the bomb's not being point and click surely nerfed his ability to cheese, but they gave him a gamebreaking AOE stun to make up for it. His Q stun is decent in length and has almost the AOE of like an amumu ult which is absurd. granted you have to land two bombs, but still. there are aways to do that. you can slow the enemy making a double bomb easy.
not to mention with max cdr his bombs have like a 5 seconds cooldown, so even after a double bomb in a team fight you can do it AGAIN.
his bombs assuming you use them right are 300 (+90% AP) at max rank, and if you times that by two, landing the double bomb....that is 600 (180% AP) ratio on one target possibly more if that single target who is probablly dead now doesnt get away from the teammates.
never mind that you can use it again in 5 seconds. that is some scary shit if you can land it.
If people ever can land the Q's consistently Zilean will be a strong pick imo just because of his team fight offensive ability, gamebreaking CC, 99% slow/speed up, and 40 second GA.