Importing from China is like a one way street, goods are exported, but even if there are major quality issues, they can’t be imported back into China.
This means, any ‘quality mistake’ the factory has made, you (the importer) are going to be stuck with it. So the right time to discover ANY quality issues is while the goods are still at the factory in China. If you catch the problem here, your chance of resolving the issue is high and this can save your business money.
This is why, quality control on any and every shipment is a must for any business importing from China.