Hi, we live in a society. People who bankrupt themselves out of whatever money they have earned and become a burden to the society at large via homelessness/welfare/crime. Which is also the same case for hard drugs (traditionally this was originally a problem with opiates). I personally do not care if you decide you want to kill yourself with heroin, but I do care as soon as our taxes are used to deal with you as a side-effect.
So making reasonable laws that curtail some of the worst things you can piss your money away on to curb crime/homelessness/welfare/er-bill-delenquency expenditures seems like a wise decision.
Libertarian thinking tries to ignore these side effects but they are real.