That's true, but it's also really hard to do for a new company or new technologies. Dropbox started on AWS, so they don't have much experience running their own

That's true, but it's also really hard to do for a new company or new technologies. Dropbox started on AWS, so they don't have much experience running their own datacenters. They'll probably adjust their depreciation schedule in the future when they know better how long useful life really is.