As a part of the deal, the tobacco companies were "exempted from private tort liability regarding harm caused by tobacco use". A much more just settlement would have allowed everyone who was harmed by tobacco (at least the ones who started smoking in the period between when the tobacco companies knew that tobacco was harmful, and when the publicly acknowledged it) to sue the companies for the cost of their harm.
This would of course have immediately bankrupted every tobacco company.
The perverse outcome of the tobacco MSA was that state's payments were tied to tobacco usage. So if tobacco usage went down, so did their payments.
This pretty much obligated the states to transfer their interests to investors of the securitizations in order to reduce the obvious conflict of interest.
This would of course have immediately bankrupted every tobacco company.