Welcome to Gaia! ::

mine is ureu!

the quincies were killed because unlike the shinigami who take responsibility to purify hollows when they kill them when quincies kill hollows they are destoyed and makes it impossible to purify them because of this occurence was constantly happening with hollows it was distrubing the natural ballance of reality in the human world which would cause easy passage for hollows of menos grande level and because of a fear for a vasto lorde class menos grande that possess far more power then a captain class soul reaper can handle appearing in the real world it would be catastrophic so in order to prevent this they tried their final souloution to annilate all the quincies to prevent this from happening but this is no longer something that soul reapers care about since that vasto lorde menos grande are starting to become arrancars and easily accessing the real world so killing the quincies is not something that matters now.