Amusing as “dumpster fire of a company” is–and it is amusing, and I am surely stealling it–I’m not quite sure what you mean by “base their syncing infrastructure”.
If you’re referring to why L&L chose DropBox for iOS syncing, L&L has already answered this numerous times on the various “DropBox is the devil” posts. See the thread below & the Knowledge Base articles linked therein for example. The short version is that, as per L&L, DropBox is the only company that currently provides the programming interface necessary to implement the syncing hooks for iOS Scrivener. If/when another company provides those hooks, then perhaps L&L would consider adding another syncing possibility to iOS Scrivener. But that other opportunity doesn’t exist now, so DropBox is it. Your choice is to live with Dropbox, or use iTunes, or drop iOS Scrivener for another tool that uses a syncing service you are happier with.
[url]iCloud Sync]
But if you are referring to syncing desktop Scrivener projects across different machines, there is no syncing infrastructure. The syncing service is invisible to Scrivener. Scrivener doesn’t know and doesn’t care. L&L recommends DropBox in this scenario, because most of the other services have a history of mangling Scrivener projects. But there is no syncing police–use whatever cloud service you feel comfortable with.
Jim