It's the same thing as why would any shoot a spike into their veins to get high on heroin. The lack of empathy for an addict is telling. The indignity of a righteous ex is insufferable. How someone became an addict is not necessarily relevant, but once they're hooked quitting is not so simple as those unable to empathize while on high horses want to think.

It is however annoying when the addict does their thing in public with zero fucks to give for anyone else around them.