In my case, my motivation has always been to improve, both for myself and for my family; knowing that there is more out there than I know gave me a reason to learn. There were always obstacles, but every time I overcame one, I became stronger and had achieved a small victory that helped me climb another step. I always say that life is like a staircase... there are all sorts of steps, and it’s worth climbing them.
I wonder if anyone had the motivation to get worse rather than improve.
If someone wants to ruin their life, they might just do it. It would be self-destructive.