@TNT261 Hey man, sometimes admiring someone doesn't require that person to admire you back, especially if you consider that forcefulness is the quintessential appeal of "delinquent" characters like her. For what it's worth, Gyari is always friendly to her fans, despite evidently not being attracted to anyone besides Kuromu.
This isn't even considering the differences between humans and demons. It's really no surprise that Gyari is well-loved by a society that exalts violence and vices. You can also attribute Merun's sudden betrayal to the whimsical nature of demons, similar to how Misfits acted in Harvest arc and even earlier.