I don't think any instructors in this thread are advocating this position. The fact that people ignore or forget their training doesn't imply that someone is actually teaching this. Stop connecting dots!
If I recall, and I don't have my books in front of me, that both PADI and SSI say you should dive within your experience and training.
Some people seem obsessed with thinking in the extreme. Yes, all recreational training agencies recommend diving within your experience and training. As I mentioned earlier, some people take that notion to a ridiculous extreme and do not believe the diver should be allowed to make any sort of judgment about the degree to which an approaching dive is within those limits. If you only dived to 37 feet on your training dives, does that mean another course is required before you go all the way to 38 feet? Some apparently think so. Me, I think the diver should be able to make that decision.
PADI specifically in its OW course recommends that before diving in conditions different from your experience that you should do a local orientation dive. Before I visited Seattle a few years ago, I had never dived in water colder than 55° F, and I had never dived in that area, where tides create a variety of experiences at different dive sites. I therefore contacted some very experienced divers in that area, and their knowledge of the local tidal issues helped us plan dive sites. I was pretty sure I was going to be OK with the colder water temperatures because I brought my thickest underwear, which I had almost never even tried on before. It turned out to be a mistake---I did not need anything that warm. I was sweating after a one hour night dive. My decision was wrong, but I made it knowing that either way the worst case scenario was something that was merely a matter of personal comfort and not safety. I put that information in my knowledge bank for the next time I dive water in the high 40s. I believe what I did was exactly what PADI had in mind when it tells divers to get a local orientation. I do not believe that PADI meant I had to take (and pay for) a formal class in diving those lower temperatures and those specific tidal conditions before I got in the water.