Can I ask the Erena fans what they think of her 'sexy' side? Did it make you more or less of a fan?
What I'm trying to say is; if I were an Erena fan, I'd dislike her doing all these 'risky' shoots because it would affect the way people view you. For example, Yuki got a whole load of new fans after her revealings pics. As a result, people might jump to conclusions when you say you like Yuki (i.e. you're a perv). ...if that makes any sense

In Erena's case it's a bit worse because she's still pretty young.
The short answer would be to not care what other people think, but as social human beings that always plays a part imo, maybe even subconsciously.
Btw, I'm not negative about Erena or her fans, don't get me wrong. She's been growing on me lately.