It's ironic that in a world that teaches and believes in relativism and no objective knowledge, truth, and morality people are all of a sudden worried about objective truth.
In general, this helps people who want to argue on ideological grounds rather than hurting them. It's bad for people who want to treat somewhat arbitrary concepts as objective to stifle debate.
A good example: gender roles vary so much culturally and possess so many outliers in the data that attempting to argue for an objective ground truth almost invariably ignores or dismisses numerous counter examples.
"M&F seen as having different natures" "F->M direct child care" "M->F more competitive" "M->F greater spatial range" etc
Steven Pinker talks about this (and much else) in this speech. Skip to 26:56 for this particular point. https://www.youtube.com/watch?v=n691pLhQBkw
An objective truth doesn't have to apply to every individual without exception, to be an objective truth. It just has to be a consistent trend. So M/F differences like the above really are objective truths, the same as "men are taller than women" or "cougars are more dangerous than goats".
(edit: this is not to say anything prescriptive about what ought to be done; it's simply a descriptive statement. Of course Pinker covers all this ground; I recommend the whole talk)
I agree with this. We can objectively say, for example, that in the US many women end up as primary care providers for children. We can even note that because of breastfeeding & postnatal recovery we expect to see women become primary care providers.
But what I'm hinting at is that a lot of people are using "objective facts" as a code for extremely prescriptive speech right now on the grounds that the observation of majority means that that majority is correct, hence my mention of gender roles.
A lot of criticism of the notion of "post-modern" thought is that it questions norms previously thought to be purely objective. The degree to which one does this is of course an individual thing and we need to constantly affirm the boundary beyond which it no longer makes sense to erode the pretense of objective truth (e.g., the Sokal paper).
And while objective truth does exist, I think the moral panic recently about being "post truth" is a little hyperbolic. Tabloid-style media has been a major issue in politics since the printing press was invented.
And while people might complain about the "other side" being in an echo chamber, I'd suggest that in the internet age people are less isolated now than they have been at any point in human history.
It is exactly BECAUSE of the lack of isolation that people are butting heads so often right now. In previous years different local communities would receive radically different media that only re-enforces their previously held beliefs.
I guess my point is that while objective truth is in fact real, both sides also have truths that they claim are objective while in reality they're relativistic. Just the issue of coal alone brings that to light with both the left and right having their objective truths, neither of which encompass the entire picture.
Here is where I don't get people: my default intuition when facing people with firm beliefs that conflict with mine is to broaden my picture and see what happens when I include other side's arguments in it. But it seems that this line of thinking is for some reason hard for many people. I'm not sure why.