I suspect this was driven by frustration. HMG are driving hard to push government to citizen interaction online to reduce costs and speed up the transactions.

I suspect this was driven by frustration. HMG are driving hard to push government to citizen interaction online to reduce costs and speed up the transactions. The financial transactions are a huge amount of money passing over the Internet leaving aside the serious duty of care they assume for vulnerable or at-risk citizens. This relies on knowing who is driving the browser you're transacting with. when you're dealing with the entire population there are a lot of people who it's difficult to establish a valid identity for. Knowledge-based authentication is the 'good enough' answer used by commercial providers but for a significant proportion of the population it's broken by their social network use and footprint.