You're right, they're two different arguments. But I don't think it's a far leap looking between different countries to say that good infrastructure, healthcare, welfare and through sensible regulations an empowered workforce is also good for the economy.

Looking straight at GDP (even if it's a blunt instrument), Ireland hasn't reaped a lot of rewards there either [1].

[1] http://www.tradingeconomics.com/ireland/gdp

Ireland was hit hard by the financial crisis; change the time scale on the graph to MAX to see the rewards Ireland reaped before that.

And their growth over the past few years appears to be back to pre-crisis speed.

They started lowering the corporate tax in 1995, so if you look at the graph from 1995 to now and compare it to the US graph from 1995 to now, the curves are nearly identical, only the US is much less fluctuating.

If by nearly identical, you mean growing twice as quickly.

That page allows displaying both on the same graph (compare to "US GDP") and when placed by side by side it's easy to see that Ireland has grown at least twice as quickly since 1995.