It boils down to this:
The government wants to make it everyone's responsibility to earn £950 a month, which is 35.42 hours per week at minimum wage. This is not an unreasonable desire from their perspective.
There are barriers to this goal, namely the lack of (nice) jobs offering these hours, the prevelance on zero hour contracts which stipulate no other job and finally childcare.
Childcare - The current system allows those with young children to work much fewer hours than those without children to qualify for tax credits 16 hours for single parents, 24 hours (combined) for a couple or 30 hours for those without children. It would be impractical for a single parent to be expected to work 36 hours a week and to be able to afford childcare. With a couple you have more leeway, you can try and get work in opposing patterns so that there is always someone around when the kids need looking after, it's not ideal but when you're on the bones of your arse needs must.
Zero Hour Contracts - These need fixing through legislation, the company shouldn't be allowed to prevent you seeking extra work (or punish you through reduced hours for doing so) if it isn't prepared to give you a minimum number of hours per week (I'd argue that that 35.42 number would be good).
Jobs offering full time hours - These DO exist, they're just not necessarily doing what you want to be doing. My DP has been trying to upgrade from 20 hours per week to full time and is applying for (and getting interviews to) a variety of jobs such as kitchen porters, laundry assistants, cleaners, warehouse packers etc, basically any job going because we need the money. She might end up having to work weekends and we'll end up spending less time together as a result, but at the end of the day you've got to take responsibility for yourself and make the best of things.
Location is going to be a huge issue to people and is going to become worse over time. There are certain areas of the country that no amount of regeneration money is going to fix, nobody is going to open up new retail areas if there's no money in the area. One of the worst things that home ownership has done is lead to an immobile workforce. There are towns and villages around the country that grew up around industries, the industries didn't move to the people, the people moved to the jobs. This needs to happen again.