The UK's Child Benefit spending programme is too broad. It was conceived amidst the devastation of 1945 - a far cry from where we are today - and it benefits people who don't need it... except to compensate them for paying higher taxes.
In other words, higher income earners are fussing over the withdrawal of the Child Benefit because they don't trust the government to reduce their taxes if the Child Benefit is removed. Their focus is on being 'no worse off'. Officials know this, because this phenomenon is relied upon to 'sell' new spending programmes.
So, like the plan to raise the personal tax allowance, narrowing the Child Benefit provides a golden opportunity for the government to restore faith with those who pay taxes, rather than to continue the proud tradition of cynically preying on their greed and fear.
That means the government has to be really clear about how a more efficient benefits system is going to mean lower taxes.