Like I said, what you choose to believe is going to boil down to your view on Hillary Clinton. If you view her as a secretive person, which you obviously do, you will be more likely to see this as a ploy for secrecy rather than as an attempt at being more efficient or convenient.
I personally believe that it's more likely that this was simply a matter of her trying to circumvent the rules for the sake of convenience. Why do I believe that? Because I've worked on countless government contracts where I've caught countless government officials doing similar things. Everything from Generals using Dropbox to work on stuff at home to high ranking officials forwarding government e-mail to their Hotmail accounts. This kind of OpSec nightmare is a daily occurrence in the government. It's dumb, it's illegal, it goes against policy, and everyone who does it should know better; yet when I worked IT Security for the government, we caught people doing that all the time. Thus this fits with a pattern I am well familiar with. This isn't something unusual to me, I've seen it a million times. The result is always the same, the senior officials come from a generation before the Internet and fail to comprehend the gravity of what they are doing; they just wanted things to be convenient and it didn't occur to them that maybe installing "Go to My PC" on their government computer or whatever nonsense they came up with wasn't a great idea. So, when I see something like this from Hillary Clinton it fits a pattern I am well familiar with and I merely think "well...at least she built her own server rather than forwarding everything to Hotmail" (yes, people old enough to be doing this kind of nonsense tend to use Hotmail, not Gmail).