Let's talk about how pocket hole joinery is supposed to work. We'll also talk about how I'm using it and why.
When you join two boards together with pocket holes it's important to align the hole so that it screws into the crossgrain of the second board like in the diagram above. If you were to rotate the board on the right 90 degrees, the screw would be trying to bite into the end grain of the board where it would be more likely to loosen.
In the picture at the top, you can see all of the painstakingly cut support boards that hold my floor joists above the concrete. These are held in place using pocket screws, but they're not installed "properly" per se. The holes are drilled into the side grain and the screws bite into the end grain of the short support pieces. There are two reasons why I'm doing this.
1) The joint is under compression due to the gravity that I had installed in my workshop. It's pretty reliable.
2) When I pull up a section of plywood to get into the floor, the pocket screws are right there on top. I can very easily remove a support piece and just as easily drill new pocket holes to relocate that piece. This gives me a tremendous amount of flexibility when configuring dust collection ducting under the floor.
It's part of the vision. I sit around thinking about every stupid little detail of the workshop build. It makes my brain hurt, but it's progress, right?