Why are commuters unhappy over the SimplyGo switch?

Commuters have expressed frustration since the Land Transport Authority announced that EZ-Link and NETS FlashPay cards cannot be used on buses and trains from June. Why is there a shift to the SimplyGo system? What is the difference in payment types? And what could the authorities do better to communicate the change? Steven Chia gets answers from Sumit Agarwal, professor at the School of Business at the National University of Singapore and Walter Theseira, who heads the urban transportation programme at the Singapore University of Social Sciences.