The thing is that the government is more focused on getting tax income from cryptocurrency traders and that is why they are going for the kill. After the PayTM bank fiasco wherein a lot of accounts were connected to a single PAN and all these accounts were used for money laundering, it is clear that the government suspects those 4000 accounts are linked to the same issue.
As far as I know, the failure of paying taxes will only result into penalty/fine added with the amount they are supposed to pay and in rare circumstances the individuals maybe imprisoned even after the notice period and not given any valid reason why they haven't paid so this drama is just to increase the tax collection from the people who were doing something to survive.
The rich in this country have been known to evade tax or steal taxpayer's money and run to another country. That has been done for many years now under the watchful eyes of the government and still, they cannot get hold of them. That is why they are turning to those who are not rich but may be pawns of the rich or maybe genuine traders or maybe middle-class individuals who can easily be held responsible for the loss to the exchequer and their incompetence.
We can debate about the dirty politics all day long, but that is what it is and still they are going to be likely be in the power in the upcoming election too due to corruption of opposition part in their ruling period. And now Modi government is planning everything perfectly to keep them in power by making their agenda to majority and media power.