There's almost no downside. Some male buyers will buy a game just for cute girls (see: LGPE), and young girls are not turned off by having a game swamped with attractive females. Look at Sailor Moon, the anime pandered heavily to otaku but it was still loved predominantly by girls and women.
The only people who dislike sexualized female designs are SJW and other feminist peasants, too stupid to realize that the personalities are far more problematic than the designs.
