Gnosticism is not a religion. Gnosticism does not even exist (except in the minds of modern scholars--how's that for an answer!)
A religion has certain beliefs and practices one must adopt and follow to be a good fill-in-the-blank. Gnosis transcends those.
Looks more like a Nazarene Ebionite site which historically was diametrically opposite the gnostic view though in the later form of Elchasaism there was some fusion.
I am very excited about this as I just discovered something which helped greatly in understanding the meaning of the term "gnosis". Gnosis of course translates to "knowledge" in English but I knew already it was not ordinary knowledge but rather inner knowledge of spiritual realities. I knew...
It seems that if the creator were truly a sadist he would not have allowed for pleasure in the world at all. And let's not forget all the suffering human beings inflict on other humans and animals as well.
I happen to think what was inserted later into both Matthew and Luke were the genealogies. These make no real sense with a virgin birth tale. And in Luke especially it just interrupts the flow of the story. It is possible that the nativity stories were added later than the original work as well...
Well as I say "gnostic" is a somewhat arbitrary category of thought anyway. A good example is Marcion who is considered gnostic by some scholars and not gnostic by others. The gnostic spectrum is very broad.
It is not so much that any were particularly world affirming but just that not all saw the physical world as being utterly evil. That's more of a Sethian influenced idea. All gnostics saw this creation as flawed but Valentinians saw those flaws as being still used by the Father of the All.