A pal of mine has one, his logic is that he can't afford both a hunting rifle and a long range target rifle, so this is his compromise. I don't consider it a particularly good one though. Field marksmanship is related to, but not the same as intrinsic rifle accuracy, and few hunters can shoot within 2 MOA in the field, on a live target. Neither do they need to. A heavy rifle will fatigue you more over a long day in the field, and fatigue is detrimental to both marksmanship and to the speed of the shot. Now that I'm a bit older I notice the weight of my .458 after several hours on foot in rough country, and find my .30/06 more comfortable though not as comforting.
But consider this, its only the first shot out of your rifle that matters. If a light and a heavy barrel are of equal quality, both will place the cold bore shot on the point of aim with properly adjusted sights. Game is not killed by shooting tight groups, which is the domain of a heavy barrel, so there is little need for a subsequent shot to land within a quarter inch of the first. In fact, the results on a game animal might be better if it doesn't. The wound volume is then greater when the backup shot impacts several inches away, rather than when it overlaps with the initial wound.
As a test of field marksmanship, make a short run of 25 yards, drop into the shooting position of your choice, and within 5 seconds of hitting the ground fire at a softball size target from 100 yards. Now in the field, your target isn't soft ball sized, but it might be partially obscured, and no game animal will wait around endlessly to be shot, so the hunter must fire as quickly as he can make a deliberate shot. The run will take the place of excitement and normal exertion felt in the field. If you take more than 5 seconds to shoot, consider your target gone. But if you make the shot within 5 seconds, how far did it print from your point of aim? If you can shoot within 2 minutes, the bullet hole will be within an inch either side of your point of aim, and if you manage it, can you do it on demand?