Hideako Anno did explicitly promise viewers "something to drool over in every episode". Also, Gainax in general. They knew exactly what they were doing. Some people say Anno was shocked that people sexualized Rei, but if you read quotes from Anno, he fully knew what he was doing: they explicitly promised a fan service quota. He made statements about it in interviews to the extent that (paraphrasing) 'anything popular gets sexualized (at comiket), it's been like that since the dawn of time'. He was immersed in the doujin culture himself, he knew how it worked, and had been implicit in that stuff as well.
Also, Neon Genesis Strip Mahjong aka "Neon Genesis Evangelion - Eva and Good Friends The Stripping Project!", which consists of multiple games and artbooks. Much of the Rei porn was officially produce by Gainax themselves. So perhaps outrage at Rei being sexualized was that unofficial Rei porn cut into the licensed Rei porn market ...
There is one quote where Anno attacks people reading manga (and porn) openly on trains, saying that the culture is infantilized, but if you read the full quote, he's talking about older businessmen doing this, saying the entire Japanese culture sucks, not the Otaku demographic specifically. And his solution is how much better things were under the military dictatorship of WWII, back when people had morals, so I think that can be taken with a grain of salt. It's also kind of ironic, such reactionary talk coming from a director who promised drool-worthy fanservice in every episode of his Big Show.