I just asked the question, mate. Not trying to get away with being too light for anything. My main hunting bow is 54# @ 28, which I mentioned earlier. I'm trying to learn more about this stuff, which is why I asked.
I've killed lots of deer, pigs, goats, rabbits, and foxes, with a .22lr, as well as a .222, but I've also shot heaps with a .308, .300WM, and a 9.3x62. I wouldn't recommend a .22lr or .222 to hunt medium game, but I have a lot of experience and have taken the opportunity when it arises.
Hunting over here is interesting. On one of my favourite properties, I hunt all of the game I listed above at the same spot, with no bag limits, seasons, or tags needed. I could be walking around a rabbit warren with a light bow, or be walking around stumping, and a chance may come up. If I'm not confident in my ability (or the bow) I wouldn't take a shot, regardless of poundage, etc.
Similar to rifles as well - a deer hit well with a .222 is going to be a better kill than a deer hit in the leg with a .375H+H. For most people, shooting a lighter rifle accurately is easier than a big banger.
I'm not trying to justify why I may hunt with the lighter bow. Just pointing out that I understand the argument, but I'm not trying to go out of my way to be irresponsible. My big bow is my hunting bow first and foremost, but this new one is a blast to practice with.