It's a bit depressing, and a damning indictment of the system, that most people's only hope for a comfortable retirement is basically a massively leveraged bet on the housing market.
Half-true. You only need 3-25% down to purchase a home. No one is going to extend you credit at that leverage for equities, bonds, etc (you could trade futures and options, or even 3x/4x ETFs, but that's pretty exotic for your typical investor).