If it wasn't for religion

[The Grand Nudger]

No, what I was asked to provide is a moral aim or goal provided by reality, and what I provided is the mother of all moral goals and aims, that we ought to do good.

If you want a lesser one, here: we ought not rape innocent babies just for fun.

b-mine
Here's where you're fucking the pooch.

You are supplying deontological claims, you...you are not establishing that or how reality provides them.  This is old hat in moral philosophy, the problem was articulated way back in 1739 by David Hume and then reformulated by G.E. Moore in 1903.

As it turns out, in all of that time, the best answer realism has come up with is to accept that both Hume and Moore were on to something, even if they may not have thought/meant exactly what we think they did, or been completely right. It does seem to be the case that every ought is derived from the conjunction of at least one evaluative premise (sometimes spoken but often silent) which may not itself be a fact even if the preceding claim is a moral fact (assuming there are moral facts).

None of this has a unique impact on a secular morality, it's a very broad constraint. Religious moralities must also supply such a premise. The trouble for religious moralities in comparison to secular moralities is that the only distinct facts between them are purported facts of the religions claims. A secular morality needs only to establish why we might have the goal of being good..for example. A religious morality must establish that their god exists to extort it's followers to be good (or create them to be so inclined).

That fundamental asymmetry is hard to overstate. Consider this, in the event that the religious moralities defining claims are false..then the goal is still present even though the god is not, exposing the fact that the religious morality was operating under the secular moralities explanation the entire time. If the religious moralities claims turn out to be true - the secular moralities claims are no less true on account of that, and the claims stand in competition and without need of reference to a god. The realist deck is heavily stacked against religious morality.

Yet nearly every advocate of moral nihilism, nearly every philosopher associated with that view, are atheists.

-just as nearly every advocate of moral realism is also an atheist, and secular realism is the dominant position of academia. It's not exactly news that atheism is and has been on the rise within the intelligentsia. If you get two academics arguing ethics (or anything else) it's very likely to be an argument between two atheists.