Excellent metaphor. How about this as a retort for them.

"Look fella, I wasn't around when the first drops fell. But since it rain soooo much, that the previous small lake is now larger, from the dam that burst wide open from all the new rain drops. I now have an expanded horizon of opportunity afforded to me. I now can take over previously non-flooded land and anything on it. But hey, I wasn't there for the first few drops. So don't blame me!"

It sucks, like any other retort would.

Plus, my position is really that racism has screwed ALL our minds over. This very same image could be air-dropped worldwide now that Americanism...even more specifically than Euroculture...is the dominant (dominating?) social model.