^Again, you just can't compare the scale of a planet and the scale of an entire galaxy. Some things simply do not scale up. You can't expect to model the behavior of an entire ocean from the behavior of a raindrop.
I understand what you're saying. I also think you cannot guess at what sort of reaction we'd see in space beyond Earth. Since we can only rely on Earth to gage how this would be, it our only POV.
Also, in Star Trek, we see monocultured planets all the time and that's evidence it'd be how it work in Trek.
But yeah, I'm going to concede. There's no way to know.