In France, adequately certified recreational divers (French CMAS *** divers and above) are allowed (by French law) to dive down to 60 meters/200 feet using only air (also for deco). Same for commercial and military divers. Whether good or bad, it keeps it simple (say stupid if you prefer).
So what people call "deep" or "reasonable" is also a matter of culture.
By the way, why penetrate in wrecks ? I wouldn't do that for leisure
Decompression diving was common, long before the "Tech" agencies were born.
Perhaps it's a mixture of culture, preconceived ideas and a sign of the times we live in. It's like not giving your teenage son the car to go to the Mall (which has been determined to be too far away, although it's just a couple of miles). A person's preconceived ideas can limit them if they allow them to.
As was mentioned in the other thread, the Andria Doria has been done on air (160-240') for almost 30 years before Helium was used on the wreck (I dove on her in 1980 with a group of Navy Divers). Now many people consider it something that just can't be done without Helium.
Certainly the appropriate training and experience is required, but as this isn't quickly attained, it's far easier to take short training courses that "qualify" you for such a dive on Trimix. It is another way, a safer way perhaps (which is debatable), but not the only way.