So those without mates are possibly not stable? Good luck finding a date if you work in an predominantly male area such as a northern mining town or military base. Good luck funding a mate if you are stuck in a bad job/career. Good luck funding a mate if you are stuck taking care of disabled/elderly family members. A stable personality guarantees nothing.
Of course not. You can be stable and not be interested for a mate. Or as you pointed out, there can be huge friction between a person and their mate because of a job or circumstances.
But aren't those cases a minority, a exception to the rule? Even people in the military or working in extreme areas don't do that most of their lives. And this isn't something new really, frontiersmen and sailors faced same issues in the 20th and 19th centuries (and since forever really).
I was thinking about a people who are stable and also have a chance and will to find a mate.