Sensory deprivation is known to cause hallucinations, often within a matter of minutes. People are primed to believe that sensory deprivation in the form of meditation provides profound insights, so they do. If you force a prisoner to sit still for several hours in a silent room as punishment, they perceive it to be a dreadful torture.
It's mystical nonsense. "I did a thing that made me feel better" is a perfectly legitimate statement. "I did a thing and believe it to be deeply profound and meaningful in ways I cannot articulate" really isn't the sort of thing we usually countenance on HN, because it's a line of thinking that we recognise to be dangerous.
For various cultural reasons, mainly ignorance, rationalists are unusually tolerant of Buddhist nonsense, often believing it to be essentially benign. If you know anything of the history of south-east Asia, you will know how foolish that error is. I rather doubt that a post extolling the virtues of Islamic or Christian monasticism with such breathless naivete would have garnered so many upvotes.