Sure, but again, the accounting write-off period is entirely orthogonal to how you choose to calculate your break-even point, so the accounting write-off period is really a distraction. But the "default" of 3 years is often used without much thought when customers of the cloud providers evaluate pricing, and so for the cloud providers it makes sense to make themselves look plausibly competitive when customers look at the numbers that way.

A lot of the other markup is obscured by splitting things into multiple categories, such as costs per requests, separate pricing for bandwidth etc. A lot of clients I talk to don't understand the pricing of the services they run, and the developers usually both don't know and don't care.