Sounds somewhat common from what I’ve gathered. Originally these were created before the existence of Pintips as ways for people to share knowledge privately between small groups of people for greater advantage during tournament play. After Pintips I guess people have just continued on and perhaps feel that they have more/more specific strategies than Pintips offers and they wouldn’t like to share their knowledge.
As with any competitive thing that has relatively large amounts of money on the line, people will press any small advantage they can gain. It doesn’t necessarily surprise me, but it’s certainly disheartening that people would keep game rules secret from fellow competitors.