In: Economics
1. No, I do not think Apple should be responsible for ethical lapses made by individuals further down its supply chain. It is only consumers who are demanding so much so that huge amount of raw materials are required. The only fault of companies like Apple is that they are infusing artificial demand into the minds of consumer to buy their products.
It is true that everyone is trying to be capatalistic, so does the individuals further down the supply chain.
2. In order to change bad practices, Apple should stop working with every supplier (because it is practically not possible for large supplies to differentiate among ethical or unethical miners) so thereby effecting their business in big way. Once that happens miners will reduce their profits and adopt more ethical ways due to fear of losing big business from Apple.
3. I think consumers must be aware of the ethical track record of companies while making purchases because even though they are not directly involve in this unethical practice but somehow they are involved indirectly in supporting & growing these bad practices.
4. Nestle a 76th fortune global 500 company "used unethical methods to promote their infant formula to poor mothers in developing countries. It is subject to the world's longest running boycott for the irresponsible marketing of baby milk to mothers in the developing world." Also they are involved in child labour, total water usage crossing 1 billion gallons per year.
Although people are turned off by their track record still company managed to be in fortune global 500 companies for many years (25 so to say {see https://fortune.com/global500/2019/nestle/}). This is because the company enjoys a brand name and goodwill which is hard to break and which has developed over many years. Hence the consumers opt for different products rather rather than discounting the company as a whole.
5. Definetly it would affect my decision to purchase it because I know I am involved in unethical bad practices directly or indirectly. For example I turned Vegan on ethical grounds because of so much of cruelty to cute animals. So I see where is product coming from, I abolished industrial milk (which is full of cruelty towards cow, buffaloes etc).
6. If I am the part of a third-party regulating body, I would surely do something do deal with ethically questionable business practices of multinational corporations like Apple. I would start a certification program for miners for world (esp Indonesia) where they can show that they are not using child labor, have necessary equipments to deal with mining and workers have sufficient safety armor with them. On the other hand companies like Apple have to accept only those who have certificates with them.