Well, the general idea is that shy girls are cute,but there is a limit to how shy a girl can be until it starts to get out of hand. Apologizing way often and fidgeting and stuff like that is kinda over the limit already. in any case, I think that shy fetish of mine only appear in cartoons and anime. If a girl were to be as shy as fluttershy I'd honestly don't know what to say to her in any given time, you know might hurt her feelings and stuff. But being shy in moderate, is somewhat okay. Something as in shy to do stuff she has never tried before, I mean I find girls who have a fear of roller coasters or shy to cosplay in public kinda cute, you know as in shy to do something daring. But not shy to the point where she can't even say hi to your friends, that's kinda out of hand. But probably it's just the general idea so people say it but they don't actually mean it (Probably). Just a personal opinion here.