Is common man the best to use or non investor 
IMO,investors never want to take loans for their consumption like home loan,car loan,etc then just save money and will buy the things for their needs but common man like you and me will buy the things immediately when we get the desire of it using loans but we are paying 20% of interest to those kind of loans.
The scenario you gave for a "common man" as you pit it is not to be general saying because, some people who are not investors are also careful in their spending and not using loans for frivolous things.
Common man also do investments that is why I don't want to mention non investors. IMO,investors never want to take loans for their consumption like home loan,car loan,etc then just save money and will buy the things for their needs but common man like you and me will buy the things immediately when we get the desire of it using loans but we are paying 20% of interest to those kind of loans.
The scenario you gave for a "common man" as you pit it is not to be general saying because, some people who are not investors are also careful in their spending and not using loans for frivolous things.
I'm here to talk about what most people do not for the very few who were cautious about what they were doing.
Most get into loan traps and end their life as being poor.