Obviously, I do care. I do care on the level of having strong regulation, having institutions and governments which regulate this, so that at the end as a customer when I walk into a store I don't need to Google whether a particular brand is fishing tuna in a particular way or not. I expect that the entire structure that exists for regulating and allowing these products to reach the shelves will prevent products which are made in an insustainable way. Maybe I'm a fool for expecting it to work this. But that was why I replied how I did - that I refuse to feel bad because I expect my government to prevent this in the first place. Just like I said elsewhere - I don't worry whether a phone I'm buying was made with child labour because I believe all governments involved in the production of the device enforce laws against child labour.
That doesn't mean that I don't care. But if I find out that phones made by kids or tuna fished to extinction is on store shelves I'll complain.....to the regulatory bodies. Not decide "well, I guess I'll never eat tuna ever again".
The government does not sit around reading your mind and then make regulations to match it. Even if it could, it wouldn't. The government only creates a regulation when either a corporation or a very vocal coalition of people demand it. And those two parties are working against each other anyway, making it even less likely.
I really don't know how to explain it in simple enough terms. If you don't care, then neither does the society, and thus the government. Ergo, people like you are the reason the regulations don't exist and aren't enforced when they do.