I only skimmed it, but I already saw a few problems with that link.
1) The idea that we are negative savings rate has flaws. But I won't go there; the fact that this flawed number has fallen dramatically is still important.
2) Short term, we can be spendthrifts. It is not something we can do in the long term. Yes, our GDP is doing quite well now. But, that is a fools paradise if it is built on borrowed spending.
3) The fact that strong spending helps the economy is true. But this link hides the fact that if we just got a 1% raise and kept spending the same, we'd all be better off. Our spending isn't the problem. Nearly stagnant wage growth is.
4) It assumes that we'll work well past the retirement age. In fact, people now are retiring far earlier than they did in the past. Gone are the days of working until you can't work anymore.