Unfortunately it's not just Microsoft's suppliers in Asia; such practices are common in many countries around the world. And it's also common in the service and agricultural sectors in many countries too. The people of the so-called West don't realise the half of it.
Many companies... They all do the same. They employ children in India and when some journalists discover this the say "we don't know anything about this and we will investigate" and then they continue doing the same -"business as usual".