In the long term, if we do not educate special children, the cost to integrate them in the society will be greater. So, yes, from all points of view - human, social etc. - special children should receive education tailored for them. And, oh, by the way, when developing education for them we can find ways to improve mass education. Look at the Montessori, for example, which was initially developed for poor, orphan children and is now widely used.