The main reason for this is taxes. It is the same reason why India's government is also trying to ban cash (with very negative results for the economy).

You see rich people have to use banks. Because over certain sums, using cash just becomes way too dangerous. So they use banks which means the banks report to the government and the government gets their taxes. But rich people also often influence the government (or even outright run it). And they hate paying taxes. So they want to shift some of the taxation burden on to the middle class and the poor. But poor people often use cash and sometimes skim on taxes. I am sure this happens with some of the more adventurous middle class too. For smaller sums cash is perfectly manageable.

Thus, the government becomes very concerned and does everything it can to "help" the poor move to more modern electronic payments.