Off the top of my head

This tenant is predisposed to cancer (or other medical issues), which means an increased likelihood of them getting stuck with massive medical bills and financial hardship so they would have a harder time paying rent on time, better Jack up their rent so I can get my money’s worth out of them while I still can or just deny their application altogether

This tenant appears to be part black, Jewish, or some other ethnicity I don’t like, better find a reason to jack up their rent or kick them out