My definitive answer is yes, no and maybe. It depends on who is using it. If you have a steady hand and know how to use it, then yes. If not, it is no or maybe. I use a monopod all the time, particularly when I am traveling but I also have a condition known as essential tremors, so if I am touching anything that is connected to the camera it is going to shake. I can normally hand hold at a shutter speed of 2 times 1/focal length but if my shutter speed is equal to 1/focal length, I will get shake. If I use the monopod, I can shoot at a shutter speed equal to 1/focal length, so it helps.
Where it really helps, however, is when I can connect it to additional support. I have a small ball head on the top of my monopod and carry a velcro strap with me. That way, if I have a post, railing or other stable object, I can strap the monopod to it, use the ball head to level the shot and fire away. Doing it this way, it is just a stable as a tripod.