I tried to be comprehensive when I made up the list of reasons why I thought Clinton might have used a private email server, but I still had a sense that the list wasn't complete. I think there might be a fourth possibility that jibes a bit with what she says: An adviser, perhaps Eric Hothem, said something like, "why don't we set up a private email server for you, there's no reason why you need to use the government email address and that way you'll have complete control of your emails and they'll be stored in one place." Neither she, nor this hypothetical adviser thought much about the repercussions or the problems.
I don't know that this scenario makes her look any better. It suggests that she formed an idea, and then went forward without thinking about the repercussions, and without reviewing the idea with any people that were knowledgeable about the issues involved or she ignored their advice if she did receive it. It is possible that she didn't form an explicit idea in her mind when she went forward with this that she would violate archiving requirements and defeat FOIA requests. But that is certainly what her actions accomplished. And it is hard to understand why eventually she wouldn't have complied with the relevant regulations until she was forced to unless it was he intent to never provide her emails to the State Department.
On a slightly different topic, Clinton's spin that that they had already used this server so it wasn't a big deal to just use it again for her private email server doesn't seem all that useful of a defense for her actions and it is to some degree not accurate. Somebody applied for and received a new IP address for the server and she is reported to have spent $5,000 on having somebody setting the server up for her purposes. I realize $5K is chump change for a Clinton, especially if her foundation paid for it, but still she initiated activity that involved some effort so that she didn't need to use the official SoS address.