He has a family and dependants to feed and protect. Obligation.
Suicide and death are uncomfortable and daunting. Cowardice.
It'd be easier to abandon his family and find his feet. He doesn't. Happiness.
The unknown of death. The stigma of abandoning another. Pain. Fear.
An unfailing desire to succeed or change beyond realism. Stubbornness.

Maybe. Who knows.

Yes, all those are very good reasons.
I'd say that they all come from the first one though, obligation. He has a duty to fulfill, someone to live for.
Yet, if I were in a situation like that, I'd wish I were just "free to go".

I've heard stories of Chinese families that had horrible life conditions during Mao's regime, some families made "collective suicides" to escape the horror. I know it's really gruesome, but it is mainly because death is "demonized", popularly taken as something extremely tragic.

Other cultures treat it as a natural thing, just like life. They just "let go".