An open cloud definitely prevents vendor lock in. It encourages innovation and makes vendors more valuable if they provide superior service or are more agile in handling a customers requirements. The costs of cloud services can sky rocket. With a cost of roughly 4/5 months of that cloud service equaling what you could have paid for the same amount of hardware the ROI is there. If you bought your own hardware and setup your own cloud inside, you then pay half the yearly cost for the same service. Open source communities are excellent, typically having great documentation or sources to learn how to achieve your goals. This makes it reasonable to voice opinions that lead to a faster advancement in the overall project.