since there's no available options,
There are basically two reasons :
- To make it look more profitable for the debtor
- The bank offer a lower initial rate to reduce the risk of Bad Debt Expense.
When bank offer a loan, there are always a risk of the debtor not able to return the loan. That's why bank lower the initial rate at first. After a set period of time, when the debtor became more financially stable, that's when the interest started to increase so the bank could gain some profit
