The server kernel is designed to require fewer reboots, actually, and the default is to auto patch and perform shutdown/restart on low-activity but that doesn't change the point, which is that there are so many reasons -- not the least of which are un-patched vulnerabilities -- that you don't do this kind of thing at your own expense if government security people are ready, willing, and able, to do it
for free.
From an IT perspective, there is one -- and literally ONLY one -- reason why you would do this, and that is so that you would be able to hide your virtual paper trail. That's it. There is no other advantage to doing it. It's like sanding off your own fingerprints.
Right, as soon as I heard she was using not just a private email, but a private server, in her HOME, it was obvious what the reason was. There is no other logical reason for doing that except that you want total control over the records, in case of investigations or legal troubles.
You do things like this when you want privacy and anonymity to do stuff you don't want open, transparent and audit-able to the powers that be.