It makes sense: people love dogs. It gives us something in common and is a starting point for conversation. And people with cute dogs seem much less threatening.
But I also kind of resent it. I wish people would want to talk to me when I'm just me.
I see what you're getting at, but also this take kinda annoys me because it falls into the bucket of implying a personal fault. If people don't socialise with you then it must be because you do or don't do X, Y, Z. "Just do X" and you'll become a social butterfly.
Based on my personal experience, I don't know if I buy it. I guess I'm a regular enough guy, but seriously almost never, across my whole life, does someone invoke random socialisation with me. Yet I know people who can't even take the bus without strangers striking up conversations and hassling them, while they are actively trying to be antisocial. What magic trick are these people performing? Can I learn the same trick? What if I don't want to perform it? I think the reality is that for some (many?) people, it just doesn't work out and it's not necessarily due to any particular flaw.
If you are naturally a distrusting person people will pick up on it, just how people will pick up if you're naturallly an open person. (The true trick is realizing that "naturally" can be changed)
Also, what about neurodivergent people who may express their openness/closedness somewhat differently? Are they screwed no matter what?
I won't say you can't do anything to influence your approachability, but I really do think there is a very large component which is essentially fixed, and people rarely acknowledge this (which is annoying).