It's not that it "matters" in a political or nationalistic sense. That's an error in interpretation of the motivation for this kind of work.

It is important because the more we know about how we got where we are, the better.

Science is useful, if it is not immediately obvious, then future generations will surely find an use for it, as it has happened time after time with mathematical ideas.

I would even say it is you who are putting a modern political spin on this by rejecting it.

For all we know, we might never get a complete picture and there might be many other aspects which we are not aware of behind PIE.