They're downvoted because it's nonsense.

The point of that phrase is to point out the ridiculousness of relating two completely unrelated items.

In this case, land mass on top of land mass is a relevant comparison, to help people who understand American geography to visualise European geography. To relate it to their own experience, and grasp why European powers see the invasion of Ukraine as a threat to themselves as well. So the phrase doesn't work. It's nonsense. Therefore, not constructive to the discussion and being downvoted.