A barren woman has to be ostracized, really? It seems Lord siva was unaware of this.

bhavasya patnī tu satī
bhavaṁ devam anuvratā
ātmanaḥ sadṛśaṁ putraṁ
na lebhe guṇa-śīlataḥ

bhavasya — of Bhava (Lord Śiva); patnī — the wife; tu — but; satī — named Satī; bhavam — to Bhava; devam — a demigod; anuvratā — faithfully engaged in service; ātmanaḥ — of herself; sadṛśam — similar; putram — a son; na lebhe — did not obtain; guṇa-śīlataḥ — by good qualities and by character.

Translation

The sixteenth daughter, whose name was Satī, was the wife of Lord Śiva. She could not produce a child, although she always faithfully engaged in the service of her husband. SRIMAD BHAGAVATAM 4.1.65

Why Lord siva didn't neglect his wife, even though she couldn't able to give him children? 

Manu samhita says, a man can desert a infertile or barren women. Sometimes you have to see with a eyes of love.