If it wasn't for religion

[The Grand Nudger]

Yeah, let's be vague so as to promote a proper discussion here ...  

No we can have a proper discussion without mentioning God or the supernatural, since whatever you mean by these terms, is something that can be separated from the question of reality possessing moral stuff.

-and since we can do so, there's nothing particularly incoherent about secular moral realism.

You may deny such a reality, but I’m inclined to see you as a solipsists, or a person who believes truth is subjective. In fact any argument you have against it, can easily to be use to make the case for the latter as well.

No one needs to accept or deny whatever superstitions or precepts you have about reality in order to discuss moral realism.  To non natural realists morality does exist in a platonic sense as some x directly apprehended by the observation of it's form in the object of x, and in a natural realists system it does not exist as such and instead exists as an empirical claim on the object x.  

What you are inclined to see is divorced from what people are telling you and, instead, conforms to your superstitious beliefs and general compulsion to shitpost about atheism on an atheist board. Further, no comment in this vein is informative as to whether or not theres any difference between religion and no religion in that regard. It may be that some objection has no valid response from either a religious or non religious pov. In that case, a realist would simply discard that moral statement as not being what they thought it was at first glance...though, to the realist, the failure of the religious pov itself is completely irrelevant. We expect them to broadly conform to secular rationalizations - but note their spectacular implosion with regards to the taboo of some particular society or culture or point in time expressed in the religious schema.

This is due to the fact that religious morality is relative, regardless of the status of moral ontology at large.