The 2 most prominent ways to hold a crochet hook are like a pencil and like a knife.
Anyone who does one and says the other is "doing it wrong" needs to take a lesson in "To Each Their Own".
I hold my crochet hook like a knife. I recently tried the pencil hold, and found it made my wrists and hands hurt. But that may partially be due to the fact that I was trying something new that my muscles didn't like.
I have seen others crochet just fine using the pencil hold, and if that's what works for them, more power to them.
Knife hold for me works perfectly fine. I've gotten a LOT of stuff finished using the knife hold.