The attraction for me is that they place their supreme being as
unknowable (much like the lesson in the Old Testament book of Job) and
look to wisdom (Sophia) as the incarnate path to spirituality. Sounds
like a step in the right direction...
Also, the Judas Iscariot Gospel mentions the absurdity of formalized
prayer or chanting as a way of controlling their god. Jesus complains
of his followers being monkeys who just don't get it about prayer and
keep thinking if they get the words right, they can make their god
respond in a certain manner favorable to them - they want to be
magicians and live in an imaginary world of unseen forces that they can
control. Much like today's fundamentalists, in my opinion.
So, Gnosticism does seem like it was a step in the right direction.
There was still the social evolution of treating others better, of
recognizing their distictiveness ("the divine within each"); and of
using learning-science-wisdom as a path to development. The rest of
their society and how it actually worked, I don't know.