This is another red herring just like pointing out that official servers suffer security breaches too. The fact that the system you’re supposed to be using doesn’t do what it’s intended to do perfectly, doesn’t absolve you of the responsibility to use it. The fact that the State department archiving isn’t up to snuff doesn’t mean you can just ignore your duty to the public to have all of your work emails preserved for the public.
Also, again, Hillary sent many work related emails to other people who weren’t in the State department, so she knew that those emails couldn’t possibly have been captured by the department, and she was informed that some of her emails weren’t reaching their targets within the department because she was using a private server. Any way you look at it, she failed at her duty to ensure that the public had full and unfettered access to her work emails.
Also none of that really hits on the fact that as head of the State department, she’s responsible for how it conducted itself, so if its system of archiving was clearly so poor, do you not think she deserves some responsibility for that as well?