This view of the universe as evil was hardly universal among gnostics, nor was the exclusivity of the knowledge. The crux of the matter was that one didn't need sacred writings or the intercession of a cleric to know God, one could gain that knowledge within oneself. The discipline that took if nothing else probably did serve to limit how widespread the practice was.
That makes it sound like a proto-protestantism, universal priesthood etc. Hilaire Belloc wrote about a protestant "temperament" or type repeatedly arising throughout history but I'm not sure I quite agree with his idea of it.
At least it makes is sound like that to me, while I do think there is a chaotic vs lawful alignment struggle in history, in most structures, if you dont like the traditional AD&D definitions you could say spontaneity vs order and I think it has been a feature of religion as much as politics, ideology, public life there is something more in the instance of a lot of these heresies.
I think we live in a time and place or culture which more naturally identifies with the heretic than the heresy hunter, in some ways I can understand that, personally I identify more strongly with the neutral rather than the lawful but I give the lawful its due as it is meant to stretch across generations and I think the authority of knowledge and learning is superior to other sorts, or more legitimate than other sorts, probably because its open, or ought to be open, to challenge.
Plus the crimes, corruption and short comings of orthodoxy are well known too.
However, if you consider for a moment, the short comings of the chaotic or spontaneous, its good or accomplishments are written in sand and wont survive a single tide, more ordered (possibly wicked) opposition is very happy to see that sort of normative pattern adopted because its easily out witted and out maneuvered, everything being learned anew so often. I've been over and over that I realise, as a RCC and socialist, there's been tons of attention to and thinking about tradition vs. innovation and I often dont realise that most people havent been through the same thought process.
Anyway, besides the whole "pragmatic" debate of "tendencies" or alignments like that, I'm prepared to take some of the accounts of heresy at face value, I'm sure that some of it IS propaganda, history is written by the victors for the most part (although sometimes victims can succeed in turning victimhood into victory, its not commonplace) demonising the defeated. The same thing has happened to Christendom in historical terms with the rise of liberal cosmopolitanism and the SJW/alt right (two sides of the same coin destroying memory and the past). However, all that said, just as tradition/authority/orthodoxy has been fully exploited by people to cover up their crimes, the abuse of children and others within the RCC for example, the "rebels" or "rogues" have done precisely the same thing, plus when you are considering times of much greater superstition and mysticism I'm pretty sure that some horrible atrocities could well have been committed in terms of belief.
Plus, I dont expect anyone else to adopt the same thinking though, the movie Season of The Witch, I thought was good, at the beginning there's a scene in which some women accused of witchcraft are being killed and it plays on the whole modern, liberal sensibility a bit I think, because you're like, how horrible, these people are obviously innocent, witchcraft? What a ridiculous idea, then one of the women turns out to be proper deadite and wrecks total havoc, I dont believe its commonplace, then or now, I dont believe that any of the world religions, let alone science, understands it or explains it or gives an proper account of it, a lot of them simply ignore it all, but there is creepy, weird shit that cant be explained and ought to provoke that sort of Lovecraftian terror thing. In that respect, sometimes, at best heresy has been one step forward, four back, or, worse, its been like giving a baby a grenade to play with.