Because people shopping at Matalan, Walmart (owners of Asda) & Primark want dirt cheap clothing.

Btw

It's not India, the factory which supplied Primark& Matalan was in Dakar , the Capital of  Bangladesh (used to be East Pakistan), Seems the 2 Owners, have been arrested, they had gone into hiding

,Just over 5 mths ago, over a 100 workers died in a garment factory fire close by, it had been a supplier to Walmart.