Both.
Echoing your point, poor communication kills. We're both introverts, and neither of us know how to hash out problems; we just bury them until one of us gives in and adds another resentment to the pile. When we first married, our discussion of kids was basically:
"Do you want them?"
"Maybe in 5 years."
Which somehow he heard as "we are going to have kids in 5 years."
If I do decide to re-enter the dating pool, I need to contend with a pool size that's about 1/20th (or less) that of straight guys. Reduce that size by half or more again for the number of people who are willing to tolerate people with right-leaning political opinions. Reduce that size again for the number of people who are OK with not having kids. And that's before we get into the other "never evers" like smoking, being ridiculously fat, etc.
There's no one out there for me. My best friend is a great guy and is also gay, but he's younger, already happily married, and I'm not his type. I will not ruin his relationship for a chance at happiness; I'm not that kind of person. I'd rather just support him, my family, and my very small circle of (largely all online) friends and hope that this void doesn't eventually become too much to bear.