alt Hacker NewsSGX on the server is breakable if and only if SGX on the client is breakable. You can either own other people's computers, or you can prevent other people owning your computer. You can't eat your cake and have it.
Yes, it might be good for ass-covering as you indicate. A lot of ineffective technical solutions are effective legal liability shields anyway. But if this becomes mainstream, the NSA will develop something they can covertly (or not) install on any such server to break SGX, so make sure you have a backup plan anyway.
Also note that Intel removed SGX from their processors because it was breakable and underused.
They removed SGX but are still working on SGX-like technologies (I forget the acronyms) specifically for server-oriented processors.
I'm sure the NSA already has various tools to break SGX but they'll be protective of that investment, they're probably not going to be using them against lower-priority targets.
I used NX and ASLR as a point of comparison because they are mitigations that are routinely bypassed - but we still usually consider them a good idea.