When the example above is made (trying to be the bigger man and not name names/shops), he gets a thinly veiled accusation of lying:
I most certainly did not mean my comment (that it's common for GUE divers in Mexico to use SM in their exploration work) to imply I believed
@lostsheep was "lying." I was pointing to the part of Lostsheep's sentence that briefly referred to "SM" and remarked that we're not hearing the whole conversation that Lostsheep had with the GUE instructor as it relates to that issue. (I know nothing about GUE's stance on rebreathers, so I have no opinion on the other bit in that sentence.)
Part of my concern is that there are reports of the requirements including buy in to the philosophy. In the thread referred to by @drrich2 a GUE evangelist described in the things one should expect out of GUE courses that being evaluated on your intent to follow GUE philosophy after the course is part of it. Not a detractor saying it's a problem, slamming GUE...... A GUE diver praising it as an expected part of the course. Hard to pass courses due to objective performance standards, that I can understand. Including philosophical views on diving/buy in or intent to always follow just those procedures as a subjective evaluation... that I can't agree with. To be fair, I am saying all of this as an outsider with only what I see discussed on SB for reference.
We really would need to see exactly how this supposed "buy-in philosophy" question is phrased, and how the student's (or prospective student's) reply to it is phrased. In Fundies, a question we got at the end of the course--in a written course evaluation sheet, I believe--was whether you "consider yourself a GUE diver." There was no other discussion before, during or after the course that I can recall that related to this idea of buying in. I believe the course evaluation had no effect on a student's outcome in the course.
Now, it seems to me that it shows closed-mindedness if a student or prospective student takes a defiant stance at the beginning or during the course, like declaring "Unless I'm diving with GUE people who demand I dive the GUE way, then I'm going to do whatever I want to do, like dive sidemount or use whatever rebreather, GUE's philosophies be damned." At the Fundies level, as I see it, all the instructor asks (at least as I interpreted what I was being asked) is that you take the course with an open mind. After Fundies, think it over and then dive how you believe is right for you. Sure, if you then want to take GUE Cave 1 or Tech 1, you will need to dive the way that is expected--and you should probably approach those courses with an open mind as well. If you have not bought into the GUE system by the time you're ready for Cave 1 or Tech 1, why would you want to take those courses anyway?
I can certainly see the situation in which experienced divers who have stuck with GUE for a long time are ready to move on to rebreathers (or some other advanced aspect of diving) and decide they don't like GUE's stance on it. I can't see anything wrong with that, and if you have earned your stripes in the diving community, I can't imagine anyone will look down on you. It actually seems quite likely to me that at some point a diver may choose to take a different path. I know of a few who have reached a fork in the road and deviated from GUE. For some, it may be right after Fundies. For others, it may be when they're ready for a rebreather. But until then, at each course level along the way, the diver at least approached the relevant GUE philosophy with an open mind. If that's all that "buying in" means, what's wrong with that?
If you want to dive with others who want to adhere strictly to the GUE way of diving, then I guess you'd need to dive that way. You just don't have to announce to the world that you secretly solo dive in the evenings. I don't think that keeping things to yourself is the same as lying, or that you will be tormented by feeling you are forced to bite your tongue. In everyday life, do we always say exactly what we're thinking, or do we take into account what we're trying to accomplish and filter our thoughts as needed? Stating defiantly at the outset what you plan to do that you know is contrary to GUE's philosophies seems to me like the former.