% of GDP has everything to do with it. Despite romantic fantasies about how we control our own destiny, we're only as successful as our nation is.
You can lift a man from Syria and plonk him in Britain and immediately he'll do better, simply because of the system he's operating in. Systems count, nations count.
If a nations system means that all your customers are too skint to spend on your goods because a chunk of their income is eaten up with over expensive healthcare, it has a perceptible affect on your income. The USA at it's zenith in the 1950's paid only 5% of GDP on healthcare. Now they pay 17.5% of GDP - and there's a perceptible difference in wealth and well-being (and thus the ability of commercial entities to sell to them).
Spending 17.5% of GDP on health, on top of taxes is insane. And the terrifying thing was that it was rising. Anyone in power would have to address this - because there is such a thing as crowding out, which has negative economic consequences.
To put it another way - going from 5% of GDP to 17.5% of GDP represents 350% inflation in real terms - would you argue this was a good thing if you were talking about any other good than healthcare?