What is driving people, projects and organizations to adopt cloud computing?
There is no single answer. Everyone’s situation is different, and everyone assigns different weights to different factors. But what is common in “to cloud or not to cloud” decision making is that fundamentally it’s like buy vs rent in housing.
*aaS is all about rent vs buy - rent is housing-as-a-service pay-as-you-go after all. You either want to be able to get out fast, or staying in one place for a long time doesn't scare you. Rent might be more expensive over time and might constrain you in certain ways (I never met a landlord who would agree to let tenants paint walls bright green, for example), but on the other hand it does not require an up-front payment and allows a certain degree of flexibility. Buy involves a commitment, but may provide some benefits (like ability to do that painting project).
The key observation is that there is no single factor that simplistically would let you choose one over the other. Rent vs buy decisions are based on personal preferences, current situation, future plans, and surrounding circumstances - all subjective. In nearly identical situations, one would choose rent, and another would choose buy - and both will end up making right decisions for themselves.
Similar logic should apply to cloud computing decisions. A popular phrase is “it depends on workload” - which is another way of saying it depends on your use case, what you are trying to accomplish and which obstacles you’re trying to overcome. It also depends on what kind of company you are, how you have been doing your infrastructure projects in the past, what your plans are, and so on.
There is no right or wrong in either case, and in spite of what some would like you to believe, cloud computing is not right for every use case. So focus on what’s the right tool for the job at hand, with an eye towards the future.