The way The Daily Prompt presents this Ginsberg quote makes it seem that the advice is to take off all your filters and throw whatever it is that comes to mind out there.
“Follow your inner moonlight; don’t hide the madness.”
If you expand the quote (which was from an interview) to the full thought, it reads quite differently.
“It’s more important to concentrate on what you want to say to yourself and your friends. Follow your inner moonlight; don’t hide the madness. Take [William Carlos] Williams: until he was 50 or 60, he was a local nut from Paterson, New Jersey, as far as the literary world was concerned. He went half a century without real recognition except among his friends and peers.
“You say what you want to say when you don’t care who’s listening. If you’re grasping to get your own voice, you’re making a strained attempt to talk, so it’s a matter of just listening to yourself as you sound when you’re talking about something that’s intensely important to you.”
It needs to be noted that Ginsberg wrote the piece he is most known for, the controversial poem “Howl”, in 1955, aged 29. The interview quote above appears to have been given circa 1989 when he would have been over 60. (Ginsberg died in 1997.) It’s two completely different world views I would think. I still find “Howl” very difficult to get through. It likely requires one to be properly drunk or drugged to appreciate.
As such, yes, I’d agree with him in the context of the interview piece in its entirety. Each writer needs to find his own voice, one that he is comfortable with, and not one that he strains to use.