China Products Quality---Good or Poor?

Many people  said China goods quality is poor,some said it is good.
what's the problem of this?
Who decide the quality,
Importer ? or Manufacturer ?
Does the manufacturer has the ability to produce good quality goods?

Before answer these,
we need know the process of the business.
1)Buyer send an inquiry to some seller(manufacturer or trade companies)
2)The seller quote the price.
3)The buyer compare the quotation and quality  and place an order to the seller.
4)The seller manufactures the goods.
5)The buyer check the goods quality ,if the quality is good,
  the seller delivered the goods.
There are something we need pay more attention here:
*not all the manufacturers do the same quality,some good,some poor.
*not all the buyers choose the best quality.
*the manufacturer produce the goods according to the buyer requirements.

There also is a problem,
many manufacturers don't have a base standard.
at least,the products should eco-friendly,harmless for human.