Dropbox is competing in a narrow-margin market wherein those margins are a function of hosting costs. At the unit cost level, it's material to their business.
Pfizer, where IT is a minor backoffice operation, doesn't care that 'everything is 2x the cost' because that cost is materially small, and the nimble nature of the cloud is a much bigger advantage. And they don't have the talent to make their own cloud anyhow. So to them it's cheaper.
Also note that most cloud users are not startups or tech companies, they are 'basic corps' doing IT.
Pfizer, where IT is a minor backoffice operation, doesn't care that 'everything is 2x the cost' because that cost is materially small, and the nimble nature of the cloud is a much bigger advantage. And they don't have the talent to make their own cloud anyhow. So to them it's cheaper.
Also note that most cloud users are not startups or tech companies, they are 'basic corps' doing IT.