1. She thinks about herself as some special snowflake and thinks that denying her entry to US for one year is a huge loss to US. It's not. She is not special snowflake and denying her entry is not a loss. The country will be fine without her.
2. Entry and right to work in US is privilege and not a right. I can stop inviting to my dinner party without any explanation and the same way US can deny you entry at any time unless you are citizen (and to lesser extent green card holder).
3. She was living dangerously. She spent last 7 years in and out of US on tourist visas. Officer was absolute right that she was abusing the system. US system is built on discretion. On B1/B2 visa at airport you are automatically granted right to live in US for six month but USCIS does not expect you to do it. Anything over one month is suspicious.
4. She applied for work visa but it did not get through. At that moment she looses key assumption for B1/B2 visa - she has no intention to live in US. The moment she applied for work visa she manifested desire to live in US which means that could not be granted B1/B2.
5. Social entrepreneur and organizing hackathons sounds like work. You could not work on visitor visa.
6. Where did she get money to live in US for 7 years? This is legitimate question if she lived on visitor visa.
PS. I think immigration system in US is borked but this is example where it worked as it is expected to work.