As someone who has to make sure that a benefits calculator is kept up to date, I might be expected to have an interest in this.
Putting to one side the competence of designers and developers (far to one side), the whole project has been comprehensively shafted by political, rather than feature, creep. The original concept of a simple benefit, which was welcomed by benefits professionals, has been replaced by an increasingly complex and, in parts, unworkable system. A top-down design always has this potential danger, as detail is implemented, but in the case of Universal Credit that has been associated with rule changes, almost all of which have introduced new complexities. Most of these have been aimed at reducing entitlement, not just by lowering rates or qualifications, but by introducing sanctions and other time based limits. Add to this localisation and devolution, Treasury ignorance and HMRC's core place in the development of bottle-necks and all is clearly going to go to plan.
The people who are going to suffer at the end of this are not just those who don't, as IDS said, vote Tory. The worst hit will be the growing number of low earning self-employed who will face a complex, monthly nightmare of reporting their accounts to DWP, having a higher notional income than their real earnings, limited carry forward of losses and their 6 months previous earnings used to reduce their current benefit.