Comment by Nevermark

And to top that off, the ratio in costs for regular vs. homomorphic computing, is far greater than the ratio of costs for using other's servers, which might be monitored for "safe" or "legal" code, vs. just buying and managing your own private servers.

So if the problem is simply to hide a computation, that is already "solved".

Homomorphic computing enables hiding in plain sight, but that's not necessary to simply hide.