I didn't realize Mozart had a gambling problem. A quick search seems to suggest several theories about it, though, saying that it's unlikely he had a major gambling problem that led him to squander his wealth. Regardless of the exact reason, financial management and having the discipline to control our spending urge are important.

I don't know any famous people who died in poverty, but I do know some of them who take such a huge risk that puts their assets at risk, such as taking a big loan to trade on exchanges. Seems like they also need to improve their skills every now and then.