The point is that there's enormously different implications. If comp stagnates less than productivity then you have a huge bargaining problem.
If comp keeps pace with productivity but is all eaten up by healthcare costs, either something caused people to willingly spend much more of their money on healthcare costs than they'd do earlier (aging maybe? obesity maybe?) or something is going crazy with healthcare expenses.
I've heard persuasive evidence that if you control for obesity the costs look ok actually.
Previously (example numbers): Median compensation is $55k + health insurance.
After: Median compensation is $55k + health insurance.
"So nothing changed?"
"Wrong! Health insurance costs more for the same benefits, so really, you got a raise!"
Yeah, sorry if I'm not celebrating.