The thing is that sword cuts both ways, the article uses 89,000 dollars as an average household income. That infact would have been in the top 1%, 40 years ago.
The government can't "invest" trillions of dollars. What would they "invest" it in? Government paper -- that's just shuffling money from one pocket to the other. Equities or corporate paper -- do you want Washington owning the S&P500? Mortgages -- that was Fannie/Freddie...