Here's perhaps a little more perspective on the purpose of hot loads.

I own a 44 magnum, which is quite capable of being used for hunting deer, elk, black bear, just about any big game in the lower 48 that can be hunted. The nice thing is I can also use this same firearm with different loads for self defense, small game hunting, and target shooting. Each use category has a different load characteristic. For instance, I like to use 300 grain Jacketed Hollow point bullets with a muzzle velocity of 1,300 fps(feet per second) or so for hunting elk and mule deer. This is a hot load (the maximum load my firearm and the cartridge can stand) that results in the optimum chance for one shot kills at a maximum limit of range under field conditions. Hunting can require the absolute limits of the firearm and the cartridge's potential.

For self defense, I find that hot loads in my 44 magnum are excessive and do not improve the statistics. Typically I will use 240 grain Jacketed Hollowpoint bullets at around 1,100 fps(feet per second) or so. This is a lighter, slower load than for big game hunting, because self defense doesn't typically occur at maximum ranges, and because humans are not nearly so tough as most big game animals. Also, shooting the hot loads can be a little uncomfortable. There is more felt recoil, and the muzzle blast can be excessive compared to lighter loads. In a self defense situation, I would favor quicker, more positive manipulation and control of the firearm while firing than I would need while hunting big game.

Likewise, when hunting small game, such as grouse, rabbit, various varmints, I would tend to load lighter than self defense (such as 44 caliber lead balls) except in cases where range is more a factor. The conditions may even warrant the use of shot loads (a capsule full of particles called shot that, when fired, breaks open and provides for an area of effect distribution of impact, similar to shotguns). These are both effective at harvesting small game (I've even nabbed bullfrogs once or twice) as well as controlling pests at limited ranges to avoid over penetration and unintended secondary impacts of undesirable targets. These loads have little recoil and may not be usable in semi automatic firearms.

Hot loads do have their place. In smaller firearms, hot loads may only serve as self defense loads, and may not be suitable for big game hunting at all. They may be legal to use, but I would not consider any hot 9mm parabellum handgun load to be an ethical big game round.