This is a great point.
The electronics industry is currently facing a lot of pressure to comply with environmental and human rights-oriented procurement legislation. These laws originate in the US, Europe, and other parts of the world. It is highly complex to understand the rules and to know whether or not they apply to a particular company.
Let's say, for example, you buy tin and produce tin cans. (This is a simple example.) You likely buy this from a distributor who buys it from a distributor who buys it from a wholesaler, etc. At some point this leads back to the smelter, at which point it becomes more difficult to trace. Which local, regional, or foreign mines provide tin to that smelter? What are the working conditions at those mines? Do the countries where the mining takes place even have applicable safety laws? How are these laws enforced and how likely is it that penalties will be applied fairly and justly? It gets complicated real fast.
Now, turn the complexity way up to the level of, say, Apple. The amount of money and man hours it takes to understand the operations and policies of your first-tier suppliers is already insane and an enormous undertaking on its own. How many second-tier and third-tier suppliers do each of those companies have? What about those companies - how many employees do they have and where do they but all of their materials? How can you verify accurate information is being shared about the composition of their products, how they treat their employees, and the trustworthiness of that data?
Personally, I'm inclined to believe the gentleman's email. They're on the right track and doing good work - there is simply A LOT to know and A TON to do, and it requires a comprehensive effort by a lot of parties that flat-out don't want to work with one another to even start to move the needle.