I think its a popular style for two reasons
the first and foremost being Fashon, in that currently its quite a large pop culture source
secondly, the style: Some of that is the classic \"big eyes\" composition, whilst this characteristic is not as all pervasive as most beleive, it is a somewhat integral part in what is recognised by the west as its most distiguishing feature, and when one considers that in all facial expression the eyes are what show 80-90% of the emotion, not surpising when you consider that young babies whilst still developing their sensory abilitys first visualy recognise their parents/carers by their eyes
and some of the style is in not only the visual direction but also in the writing style. What with most stories being culturaly influenced it stands to reason then that if a story is written from a different cultural perspective it will have elements both exiting and unseen in the foreign cultures it is introduced to .
or you know, it could just be me...