A few things come to mind:
1.) I try to acquire a decent, well-rounded grasp of recreational scuba diving. Not tech., no dive professional credentials, etc... So when an agency becomes known in the North America and Caribbean region by impact (real or potential on the hobby), I wonder what the 'buzz' is about.
2.) GUE Fundamentals has often been cited as an excellent self-improvement course for divers, as opposed to pursuing a path to become a dive master, instructor, the PADI Master Scuba Diver qualification, etc...
3.) We know GUE draws on DIR and considerable thought goes into how they do things, so the opportunity to learn from their wisdom may be there. Why not hear what they've got to say?
and then never perusing training with GUE.
If this part is a big piece of what you're curious about, okay, let's consider why not?
1.) People can learn an idea or two without paying for a course, plane tickets, etc...
2.) I'm a mediocre intermediate diver and historically slow to pick up motor skills. If GUE Fundies is taught to a high standard of performance, I'd need to find a bald instructor so he didn't pull his hair out dealing with me. I question whether I'd be up to the 'challenge' of really getting the benefit out of the course.
3.) My gear isn't GUE compliant and I don't plan to change it. Yes, I dive a BP/W setup. I had a dive shop guy assemble it for me; after watching that ordeal, I'm not willing to change anything (other than I took my crotch strap off, thinking I didn't need it, learned I was wrong and put it back; I also put on a 2nd tank strap). But if I understand correctly, my Hollis Elite 2 harness would not be compliant; GUE wants a single piece webbing setup. That may sound petty, but I'm not a 'handy' type, and I like my current harness.
4.) I'm retired and money is way tighter than it used to be (although time is much better).
So, someone of uncommon patience and compassion would have to be teaching at the local quarry and overlook my deluxe harness. Then I'd have to convince myself the benefits over my current diving ability would be worth the expenditure of family money. I'd be looking to improve my diving ability and ideally earn a rec. pass.