"Singlism" is indeed potent and double-edged. Because most people still do opt for marriage, this bias probably hurts more singles overall. But the intolerance that couple people feel is no less real or harmful.
So those are my two choices? Either I'm providing for my family or I'm out to boost my ego, my status, and my self-image? Touré, there are around 100 million adults who are not married, and that's just counting the ones in the U.S.
To be single at heart, I think, means that you see yourself as single. Your life may or may not include the occasional romantic relationship, but you don't aspire to live as part of a couple for the long term.
There's something troubling about the use of the word "relationship" that excludes all relationships but romantic ones. All other adult relationships aren't just excluded in the wording; they're absent from the studies.