a reason for long-lasting defilements

Some other asker had said something like ‘trapped in defilement’. I thought it was interesting b/c I feel that way a lot. Can karma (results) have a long-lasting defiling quality? Or is this just an excuse for a weak-minded one to continue along? For example, someone who is in hell is there for a reason, and while there, the mind is defiled and hasn't a chance to become undefiled due to the karmic energy…but after the hell period is completed, the opportunity to give effort arises. Can it be like this? on a side note, i believe some jain understanding talks about certain characters that can never be liberated, but that's another topic..