> everyone has been single at some point

Yeah but has everyone been single _all of the time_? Your reasoning reminds me of the "suck it up, we all have been bummed out before" mentality toward depressed people.

> most peoples' experiences dictate that it's probably not as bad as being poor or disabled.

Empathy isn't soap, it won't be spent. You can feel empathy for the poor, the disabled, _and_ the chronically alone.