Just because there might be a bubble doesn't mean that all startups will autofail. However, if I ran a startup with ads as my main source of revenue, I would be worried as advertising budgets are the first thing to be axed in a crisis.
For entrepreneurs crashes are the best times to innovate and launch new ventures because while everyone else is angsting about cutbacks and surviving just another day, the entrepreneur can launch lean businesses and products AND usually get great deals on people, equipment, office space, services, etc.
I seriously doubt that modern democratic-capitalist societies as a whole can avoid bubbles. Individual business owners OTOH can not only survive but also thrive in the aftermath given that some basic conditions are meet.
For entrepreneurs crashes are the best times to innovate and launch new ventures because while everyone else is angsting about cutbacks and surviving just another day, the entrepreneur can launch lean businesses and products AND usually get great deals on people, equipment, office space, services, etc.