I have a perfect metaphor for this:
"My mate Joe has £500 more than me in his bank account. He doesn't work as hard as I do, and it's unfair that he is earning more. I wish I knew his PIN number and I could get his cashcard and get the money out for myself"
Sounds a bit harsh, right?
But people keep things secret for a reason. Yeah, maybe Joe has more cash in the bank, but for sure, if he let everyone have his PIN he'd be skint.
Magic authors/writers/producers also have bank accounts. Sharing their secrets is pretty much the same as giving their bank details away, as you are effectively robbing them of their wages.
Nuff said
PS... this comment is general, and not aimed specifically at OG1yaHerd, who started this thread.