Markets can become unbalanced, but they generally correct themselves before crises become systemic. Because of the accumulation of past political reactions to previous crises, this did not occur with the most recent crisis.
The early 2012 upturn in US economic activity still owes a lot to extraordinarily expansionary monetary policy and unsustainable fiscal deficits. If income concentration could be reduced as the budget deficit was reduced, demand could be financed by sustainable, broad-based private incomes.
Powerful bankers wreaked havoc with our economy, destroyed millions of jobs and directly caused a huge increase in the national debt. These people and their successors are now poised to get out of control again.