And that statement is not really an opinion. It’s not even really economics. The statement really derives from simple maths and the basic nature of deficits and national debts. Put another way, the statement derives from the book-keeping entries done by governments and central banks.
That “QE” point does not of itself prove there is anything wrong with QE (not that I’m a QE fan). It simply illustrates the basic point in the above article, namely that monetary stimulus unaccompanied by an equal amount of fiscal stimulus leads to the government sector buying up private sector assets.