That sounds ... dismissive, but I'm not sure what's actually supposed to be wrong about "non-religious tithing".
Should we give up not working at weekends because it's a "non-religious sabbath"?
10% is a nice round figure. It's small enough that many people can afford to give up that fraction of their income without getting into money trouble. It's large enough that many people will be doing a really substantial amount of good to the world if they give that much of their income to well-chosen charities. And, yes, it happens that some religions have used the same figure, which probably helps "give 10% of your income" seem like a reasonable thing to suggest.
Is there anything bad about any of that? If there is, I don't see it.
I don't claim that there's anything optimal about giving 10% of your income. But I don't see any reason to sneer at people for doing it, either.
Should we give up not working at weekends because it's a "non-religious sabbath"?
10% is a nice round figure. It's small enough that many people can afford to give up that fraction of their income without getting into money trouble. It's large enough that many people will be doing a really substantial amount of good to the world if they give that much of their income to well-chosen charities. And, yes, it happens that some religions have used the same figure, which probably helps "give 10% of your income" seem like a reasonable thing to suggest.
Is there anything bad about any of that? If there is, I don't see it.
I don't claim that there's anything optimal about giving 10% of your income. But I don't see any reason to sneer at people for doing it, either.