Honestly, I'm guessing it's the lack of knowledge on the matter that makes people want to avoid the subject. Crypto is still very vague for most people, and indeed, it takes passion and active interest to really get into it. We listen to things like crappy colleagues, or jobs, or whatever, 'cause those are easy to compartmentalize for the listener. You nod. You hum. You commiserate. That's pretty much it. Doesn't require active listening, or an effort to comprehend since most job or colleague or family stories are the same, essentially.
That's why I think people are "bored" by crypto. Obviously, I'm sure some people are genuinely not bored by it, as I don't think this is the case with your lovely wife. But generally speaking, from what I've seen, you know ;)