The simplicity of "it's all just a coincidence" is about the same as "it's all just magic". And you would be right about the collusion explanation's need for some elements to work, were it not for the fact that we see those elements working together in broad daylight. They attend the same universities, join the same clubs, they even have a town in Switzerland that's become synonymous with the owning class meeting up (Davos).

They're not saying it's coincidence, they're saying it's herd behavior and groupthink.

The people we're talking to don't really understand those concepts. Or possibly they just reject them implicitly (which would be an even stranger explanation).

Yeah and I hear they're stinky, too.

I wasn't going to say anything, but there is a bit of overlap between them and the "deodorant is late-stage capitalist oppression" crowd.