The problem with introverts is that we by definition don't stand out. When you notice us, it's because we're being uncharacteristically social, so you assume we're just like you. When we're in our comfort zone, you won't see us at all and so you once again won't have any evidence that there are actually people out there who prefer to be alone.
One key to discovering introverts is to not assume that "introverted" means "[not] smooth with people in all sorts of contexts". At work I participate more than most of my teammates, and I'm really good at understanding people and helping build consensus, but it takes a lot out of me. If you just knew me from work you might not realize it, but by the end of the day I don't want to spend any time with anyone other than my wife.
Might as well just be someone with social anxiety. Many people like that in tech.
I had to read that a few times because I was wondering maybe there's a thing called "single husband" , but boy it's just the other usage of the word "single". English is a funny language :)
Well, you're statistically less likely to meet the introverted ones :)