Besides honest misunderstanding, there's so much FUD being spread by people on HN who are afraid that their greedy data manipulation plan for a startup has been completely foiled...
So much FUD that you definitely feel sometimes that the comments are straight out of http://n-gate.com/
Caricaturizing (a bit):
"HN1: The GDPR takes away our freedom to make tons of money from your private data! Dirty EU commies and their superstate imposing their law worldwide!
HN2: The law doesn't apply worldwide and it protects my privacy. Just block users which are geographically in the EU. Also, read the law, it's only 60 page and more readable than most RFCs.
HN2: Nah, I'm good, I'll just rely on internet FUD as my main source of info. Dirty EU commie bureaucrats!"
PS: Obviously not all comments are misguided, but good God, there's soooooo many which miss the mark by a mile...