About the gunblade cost decrease

Why? Why nerf bork by increasing its combination cost but buff Gunblade by decreasing it? Gunblade is an overpowered item comparing to bork (because both have cutlass as an ingredient). I was expecting at the patch notes to see a reason behind that combination decrease but there was no explaining whatsoever. Gunblade does insane amounts of damage with its active (175 as minimum) and gives a lot of healing which is hard to outsustain especially since the 2 biggest abusers of it are mana less champions ( ). At least you could reduce the active damage in compensation for its cost decrease. I really don't understand your reasoning behind this Rito