Naturally, those imaginary MOE girls are extremely idealized - they are kind, innocent, soft-spoken, having unlimited love to boys whose play with - something totally different from the real high-school girls, whose getting wilder and independent ever since. Some OTAKUs went into identity crisis, began to look for a girl in real life whose resemble to the MOE girls. They turned their attention to ever younger ages, junior-highs even elementary school girls. Pedophilic love has been found throughout in human history, but never be so widespread like in Japan today (at least I think). However, the connection between ever increasing sexual child abuse crime and MOE games popularity is subtle and hard to proof. In fact, no one is sure if there is actually a connection between them.
4. Postscript
After having all said, I must admit that I am a schoolgirl uniform fetish (surprised?). I think nobody will deny the fact that girls looks cute in uniforms - and it looks great only with girls in certain ages. In KOSU-PLAY occasion adult women in age of 30s, even men wear schoolgirl uniform - they just don't fit, even looks like an disaster.
I love cute girls, just as every male mankind would. Please don't misunderstand however, it doesn't necessarily relate to sexual meanings. I'm totally opposing to child abuse, I don't want to buy their love via ENJO-KOUSAI. Just watching smile on their face makes me happy, and that's enough for me.
"Don't pick the a lotus flower. Just leave her in the field, as she should be." - An old Japanese proverb.
4.1 See Also
Unfortunately, most of school-uniform related sites hit by Google are adult porn content - understantable but disappointing. Those below are the few site which provide Japanese schoolgirl information in English, without nasty pop-up adult advertisements.