So, which customers lost their data due to the bankruptcy of WorldCom, for example?
There is not worst dead than someone who don't want to listen. Evidently, in each market you lose different products
when a company crashes. If it was Kodak, you lost film/chemicals availability, if it was Enron, or WorldCom, or Lehman, it was something different. With a "cloud" company, evidently the risk is to lose the service, and in the worst case the data - being that the product. Of course the sector is still too young to see big companies suffering deadly situations, but there's no reason to believe it won't happen.
This one is indeed driven by customers.
No - because not always customers have no control over it. A new technology could, for example, made all cloud service no longer secure.
Still, no one is going to kill a cash cow.
It only depends on how milk they can extract from each cow. Remember, once a cow can't be milked enough, it's killed, and sometimes no much time is allowed. It may happen that many little customers becomes an hindrance which doesn't get much revenues compared to the cost of supporting them, so, sure, they will up prices so much to make you leave, and make space for more remunerative customers. Think it as a kind of "cloud gentrification".
Also, to be able to migrate somewhere else you need the opportunity to do so - which means you need another cloud service, or your own infrastructure to do so. If you no longer have it, and also it becomes impossible to source it, good luck...
I would be slightly more relaxed, though, if it were Google or Amazon or Adobe
Do you know how many products Google already killed because they were not remunerative enough? Ask Google Code or Google+ users, for example.
My approach is my data can be lost *anywhere". I do not trust any of the technology or companies storing them. Nor I think even the biggest company is unbreachable or can't lose data, no matter how they work to protect them.