I think the time of buy-and-hold are gone for the visible future
There is no such thing as a visible future. If you plan to retire in 3-5 years then you can make a strong case for not starting long positions. If you believe the world will not come to an end in the next 3 decades then its a great time to go long. My estimate on the 1 billion new low midlle class is just a guess, without the worlds population having at least 30% being low middle class we will have anarchy and I like to believe we will not have anarchy.