"but that they have no objective basis for morality"

That is very wrong. Objective reality can be the basis for a very profound and considerably less ambiguous moral code than those of religious nature by dint of the fact that the facts underpinning are less open to personal interpretation.

The fact we are, at the most parsimonious explanation of our existence, an aggregation of atoms, molecules and electrical signals, built from the stuff of stars and supernovae, that have become conscious and can now contemplate our own nature as the universe made conscious is profound and beautiful. The sanctity of all life on our planet, the way we interact with each other is informed by the fact as far as we know earth is the only place in the entire universe where we know this incredible event has occurred... and is explicable by science. Compassion, the value of all life and our planet's environment, tolerance, equality and understanding are at the core of many of us who have no evidence for the supernatural.

It's a moral code based on the fact life is explicable, that explanaition is rooted in science and the philosophy of science and understands at the most fundamental level is beautiful and complex and precious beyond measure. That's why we don't understand why religious folk believe they have dominion over all life on earth, and why they still seek to kill each other after millennia of slaughter, and now seek to influence debates on abortion etc when far more nuance, tolerance and compassion is needed to be sure society does the best thing for those involved.