I'm surprised at the amount of comments along the line of "Yeah it kicked my butt hard. Had to start all over...blah...blah...blah".
Sure there was a transition for me but it wasn't that effing bad. Makes me think that most didn't have their basic skills down in the first place.
I don't think that's necessarily a fair assessment. For my wife and I, we both have 10 + years of technical diving experience and over 300 cave dives each. Neither of us are perfect divers (anybody that says they are is an idiot), but we're both squared away enough to not be embarassed by our skills in front of anyone and can handle real life issues and emergencies cleanly underwater. The big issue for both of us initially was buoyancy, which I think is true for most new ccr divers. We both read about how to manage the 3 bubbles and what to expect on ccr. The problem is you don't really understand it until you're diving it. I would make a minor adjustment in buoyancy and realize it was way too big. Or I would wait too long to make an adjustment, because it's so innate for me to use oc breathing for small buoyancy adjustments. So on ccr, my brain would say I'm a little buoyant so my response is to exhale and wait, by the time my stupid meter went off to remind me that's not going to work, I'd have to make a bigger gas dump than ideal. It was just an up and down battle at first trying to get used to it. For someone with alot of experience and comfort in the wate, it truly felt like I was back to being a new diver again.
I do agree with your thoughts a little though. I dove sidemount for many many years, but believe a bm rebreather is the only correct choice for a first time unit. I never took a formal doubles class, just learned through mentors. The rebreather pointed out that I understood, but not as well as I would like, how to adjust my harness and points of leverage such as fins to achieve perfect trim without having to work at it. My first couple of months on the unit I was trimmed out well, but was extending my feet out and arching my back more than I would like and led to some discomfort. I adjusted fins and harness tightness and got it fixed pretty quickly. But it also pushed me to take GUE fundies to really get an excellent mentorship in how to really work with those things. Eventhough I was pretty quickly able to make adjustments on my unit (well enough to pass cave ccr crossover), some of the tips and tricks I got from fundies made me slap my forehead and realize I was a dumbass for missing some minor things (which would have made the transition even faster).
So I get your point, but I really believe the transition to ccr can be very humbling to a diver of any skill level. It also depends on how you plan to dive your unit. I think a single al40 slung on my side would have made the transitiion a little easier, but that's not how I planned to dive long term. So starting with sidemounted bailout from the get go was the only way to go, but it also presents additional hurdles to properly balance the rig.