Personally, I don't mind if one character is like that, I'm cool, but when it gets to the point every character has the same facial expressions, even if it's different hair and body, it's just only one face you're doing all the time. [Usually the bodies aren't too different either from my knowledge.]

That's my issue with it, too. But then again I went to art school where they would literally throttle you if you had two people with too similar of faces or anatomy in a picture (unless it was intentional and making a statement). As an animu style, I understand if a character would be in Eroge, but to have every girl character looking like that is imo stupid. Just how I feel on all of the bishounen that look alike, too :I