The Justices seemed poised to strike down the individual mandate in Obamacare as unconstitutional. They then seemed to accept that while doing so they should be as restrained as possible. The debate centered on what exactly would constitute "restrained" in this context. Justice Scalia argued that to wipe out the whole law and give Congress a "fresh start" was the most restrained thing to do, because otherwise the court would be in the position of picking and choosing what to keep and what to toss. Others like Justice Ginsburg had a more accurate view that the court should do as little damage as possible and leave Congress to fix what they wanted.
One problem I did have was that the justices seemed to worry about the insurance market if they struck down the mandate without striking down community rating and non-discrimination policies. Fair enough. (But wrong).
But what about wiping out the entire law?
millions of seniors who now depend on lower prescription drugs would be forced to pay more for medicine immediately. (the ACA closed part of the so-called "donut hole")
millions of young people, some currently using the policies would be thrown off the healthcare rolls.
major changes in medicare that strengthened the program would be eradicated.
a high risk pool that is currently serving the very sick would be eliminated
...and so on.
So there are costs no matter what the justices do. The question is what is the most restrained?
That clearly is to strike down the mandate (if they must), stay the decision for 90 days to give Congress time to deal with it, and leave the rest up to Congress. This does the least damage to our society, and gives Congress a chance to act it's will.