I would point out that right now, you have your data divided across four different buckets, which means no one provider can completely compromise your data. Why would you want to end this arrangement?
All else equal, using more storage providers increases your risk of exposure, not decreases it. And for most classes of sensitive data, the loss of any of that data can still cause problems, e.g. imagine health records... if only 1/5th of your patient data was hacked, that would still be a very bad situation (and before anyone asks, yes people use Dropbox for this[1]).
[1] https://www.dropbox.com/static/business/resources/getting_st...
I think we are in a "when, not if" world for security compromise.