Kogmaw changes revertion

Just to have a little question to those, who are doing these balance changes and reworks - why are you planning to revert changes to Kogmaw, except for his R? Funny fact is that when you were making this rework, it was supposed to be "better" for Kogmaw and it should've made his strengths and weaknesses more obvious. After that you said that AP Kogmaw will still be playable, even though it was proved to not be true, because you basically rely on your team that they drop opponents under 50% before ult starts dealing some damage. But now you admited, that his old state was the way to go with Kogmaw, so may i know why did you decide to revert everything except for his ult? Was AP Kogmaw really that strong, that he didnt deserve to stay in a game in a viable state? Because his state as he is going to be, is going to be exactly the same, just without the ult, that was pretty much crucial with him and considering that ult mana cost debuff disappears after 10 seconds now, while it was 6 seconds before (and it even used to cost 40 mana instead of 50) it just leaves AP Kogmaw in really bad state. Before it was somehow managable with right build and gameplay, but right now there is literally no reason to pick him over any normal mage like Velkoz, Xerath or Ziggs. So may i know if it was intended change to kill AP Kogmaw (because of him being OP?) or if there was any other reason for this? Thank you for your answer.