Is atheism self-contradictory ?

[FatAndFaithless]

Similarly, I consider homosexual acts to be far more gross and disgusting than child marriage, does that prove that homsexuality is inherently wrong regardless of any belief system ? If your answer is yes, then you better come up with a better pretext to condemn anybody's actions. If not, why bother with asserting it if you can't show us why think it is wrong ?

Bolded mine.

And yet you charge atheists with having no moral foundation.  This is the kind of shit that should embarrass theists, not embolden them.