The word "MAGNUM" is probably the most over used, and misused word in the shooting lexicon. Rather than being anti-magnum, we should recognize the key to field marksmanship is a balance between bullet weight, powder charge, and rifle weight, to keep recoil within the tolerance level of the rifleman.
Let's consider the .45/70. The .45/70 is not a magnum by any measure, but when chambered in a traditional lever action rifle, and loaded as recommended for big game hunting, it will absolutely destroy any chance a novice shooter has of becoming a competent marksman. This is not due to recoil alone, which is not insignificant, but by a combination of recoil and poor stock design. The only way to make things worse would to be include a crescent shaped steel butt plate.
What about the .257 Weatherby? This cartridge pretty much defines the term magnum, in that it is extremely overbore, which means that in any reasonable barrel length, the powder charge has reached the point of diminishing returns, in that heavier powder charges will not significantly equate to greater velocity. Nothing would be gained over the .257 Bee by necking down a .378 Weatherby to .257 and filling the case to the neck with 112 grs of powder under a 100 gr bullet. Yet the .257's recoil is mild, velocity of standard weight bullets is extremely high, resulting a very flat trajectory, and given an appropriate bullet, it can be expected to be effective on most big game, other than big bears and bison. Despite these ballistic attributes, novice shooters tend to shoot it well in standard weight rifles.
The word magnum was not included in the naming of the .416 Rigby, but when a 350 gr bullet is driven over 2800 fps by 100 grs of powder, shooting one demands a tolerance to recoil, if its going to be shot well from field positions. I could only manage 3 rounds of .416 Rigby from prone before loosing concentration, but I can go 5 rounds slung up prone with my .375 Ultramag. I won't attempt prone with my .458, yet in the world of magnum cartridges, the .458 doesn't really meet the definition, since cartridges of the same caliber with larger powder capacities can gain significantly more velocity with standard weight bullets. Similar observations can be made to the old British Nitro cartridges, from .450 to .600, none are magnums, all of them will get your attention, even in double rifles weighing upwards of a dozen pounds.
If a novice hunter chooses an ultra-lite rifle chambered in .30/06, this thing will likely give him grief when he attempts to zero it, if he ever manages it. The .30/06 is no magnum, but its said to be the most powerful cartridge with which a novice adult can shoot a standard weight rifle with confidence, all bets are off if 3 or 4 pounds are knocked off a nominal weight of 9 pounds (loaded rifle, 24" medium contour barrel, scoped, with a sling installed). The first shot will be shocking, not only will his shoulder hurt, he won't enjoy the sensation that's transmitted to his jawbone either. But the same ultralight rifle chambered for the 6.5 Remington Magnum cartridge will be within the novice's recoil threshold, and the chances are he will shoot it well up to the limit of his experience and ability, and take his game in an ethical manner, rather than closing his eyes and jerking the trigger, as his cross-hair bounces across a big game animal that deserves better.