Poison Ivy: I must confess, the combination of heroic derring-do and anatomically-correct rubber suit puts fire in a girl's lips.
Batman: Why do all the gorgeous ones have to be homicidal maniacs? Is it me?
Robin: I want a car! Chicks dig the car.
Batman: This is why Superman works alone.
Mr. Freeze: Tonight's forecast: a freeze is coming.
Mr. Freeze: Allow me to break the ice. My name is Freeze. Learn it well, for it's the chilling sound of your doom.
Mr. Freeze: Freeze in hell, Batman!
Alfred: There is no defeat in death, Master Bruce. Victory comes in defending what we know is right while we still live.
Chosen answer: Purely a creative decision, but based on the tone of this question I don't suppose you're honestly after an answer so much as you are just looking for someplace to express your distaste.
Phixius ★
Because Schumacher wanted to base the suits on Greek sculptures hence the nipples. Don't forget Robin's shorts or Batman wearing different colored cowls in the comics, perhaps this was a nod to that.
Rob245