In the traditions we read
اتقو الحقرات من الذنوب فانها لا تغفر
Avoid the minor sins for they are not forgiven([1]).
It may be that one does not feel shyness in committing sins considered as minor, and therefore may think it not necessary to seek repentance. One’s boldness and courage to repeat and engage in the sin is increased and thus the foundation for forgiveness is no longer available.
If someone owes a small amount of money, but boldly neglects to pay the debt, they may not be forgiven. While another who owes a larger amount but apologetically seeks an extension of time, may be handed respite and excused.
Yes, a small debt may not be excused from someone who is bold, but a larger one from an apologetic person might be!
[1] Wasaail Al Shia V15 P310