Not exactly, but really close to that.
That we have been using or recycling the same morality so long now that it's impossible to tell what could be original.
What an Atheist or even a secularist/ being many different ideals, says they put together for their own benefit is in one form or another something that's already in use and un-original.
If its an un-original form of morality, (Even though its being combined with several other forms of morality) then its still not "your" morality because you didnt come up with it.
You by yourself, do not have the ability to procreate morality.
And you can not be credited for the use of it. That comes from another source.
To take credit for using a miss mash of morality to better suit yourself still doesnt mean that you're a moral person simply because you're using moral standards and because you also did not make your own morals you can not be called morally correct for the sake of calling you so.
You're just doing what everyone else is.
And everyone else has been following a standard that has been around so long that its impossible to tell what could be the original.
Unless.
You know the original through another form that isnt necessarily morality but morality did come from it because a moral standard was needed to practice it.
Like, religion or cultural differences.
They only thing that sets morality apart are those 2 factors.
Religion and culture.
Like say, Thanking the Lord for your meal or asking him to bless it before you eat.
Thats a Christian value.
Or It's polite to hold the door for someone. You may or may not know where that one came from, but it has its origins in something and isnt something people just do.
You cant assume that just because you dont know where something came from that its instinctive and you're using your own judgment on whether or not it should be used. Because you're more than likely using it subconsciously.