I haven't got enough time to read through all the information about the decision, but is there anything in there regarding third person financial support?
Personally, I can understand the UK government wanting to set a minimum financial requirement, but not allowing a third party to support the family with a non-EEA member is taking it too far. It leaves no room for consideration of the social and financial support the family can receive to keep them from being a financial burden to the UK. For instance, students, recent graduates and people working internships have a really difficult time uniting their families, even when they have friends or families who can provide the additional support necessary. In addition, families who have been living abroad and want to return to the UK should be able to use third person support to prove their financial stability upon their return. Forcing the UK member of the family to return on their own and look for a job if they don't have one lined up, then work for 6 months or more while their family members wait abroad, is a ridiculous and unnecessary burden on a family, especially when there are children involved. Some families choose to move back to the UK to be with ill or dying parents, and they often have accommodation and perhaps even savings, though if short of £60,000+, tough luck - your family can suffer separation. It's disgusting. Keeping families apart who have support in the UK is abhorrent and inhumane. Very sad state of affairs.
Other countries including the US allow third party support for families to meet financial requirements for immigration. I see no reason other than petty pandering to a xenophobic public to exclude third party support in the UK.