Nice try, but this one's just a mistake.
If you're so sure it's a mistake, why bother creating a thread to ask what others think? I've shared what the rationale within the industry will be. It sounds like you don't want to accept it because you don't like the answer.
The fares are clearly extortionate, but they are in keeping with how industry pricing works more widely. So they're very unlikely to be a mistake.
Acton bridge is the next station south with arguably even more convoluted routing by rail geography but the fare is less than half! (And also much more in line with every other station within 10 miles).
Because from Acton Bridge it's assumed you will travel via Crewe and Stockport, which attracts a lesser premium than travelling on the Liverpool-Manchester route.
Walking from Hartford to Greenbank is not a realistic prospect for those with mobility issues or heavy luggage, to name just two categories. A walking link should arguably still be in the industry data so that it is presented as an option, but at that sort of distance you can kind of understand why it's not.
Realistically the number of people who would take advantage of fares routed via the walking link would be miniscule.