There are plenty of people earning less than that, that still manage to afford to pay their own way with kids, car & house etc.
The incentive to coming off of benefits can only be a limit of £10,000. Cruel but true.
There is also the strategy of increasing the tax free threshold to around £12,000. This gives two major benefits: 1. The excuse against getting a job after a benefit lifestyle existence is removed. 2. It's fair to say that people (the vast majority) earning less than £20,000 aren't going to deprive the exchequer of funds by stuffing their mattresses with the dosh. It'll go straight back into the economy by being spent on things that will have a 20% VAT tax take applied, with the added bonus that more jobs will be created in the retail sector, which in turn will generate more VAT and corporate tax.