[jandrese]

That assumes the cloud service is irreplaceable. Having the source to the API means if Google shuts down their service you have the possibility of migrating it over to a new service with only a minimal API change. This assumes you have some way to get your data off before the service goes kaput though, which is not always the case.

[detaro]

It at least assumes that a competing service is different enough to give the API wrapper low value, yes.