I want to know whether what you say is relevant here, though.

You speak of clouds very generally, but here's the issue: in the specific case of flight plans, would "vertically-integrating" their electronic management actually cost them anything?

As an example: electronic mail. Creating or licensing an in-house e-mail client, and storing the emails locally or otherwise on company servers, needs an investment of basically $0. This is not a function that it makes any sense to outsource.

Generalizations aside, why wouldn't flight plans be like emails here? I bet you could store a flight plan on a floppy disk. Am I wrong?