Because the problem is emissions, not who creates those emissions.

What I'm saying is that if coal does so much sequestration that it in effect has negative emissions, this is actually better than solar which has a little emissions. This is because we care about emissions.

I'll make an analogy. Let's say we have two companies that output poison in their process. Company A produces 10000 units and company B produces 5 units. Company A shifts and now produces -10 units of poison and company B doesn't change. Initially company B is better but after the change company A is better because really all we care is about the poison being produced and not actually what the companies do. Because at the end of the day, our goal is less poison. That's the number that matters.