I'm with Illmatick and Maxdalury. Smoking pot all day does not by any means make you a loser, a slob, a retard, or damaged goods. The problems that you attribute to excessive pot use are actually by-products of the fact that most potheads have to hide their smoke from the community in which they live. Here in Mendo County the majority of the population smokes all day, you can smoke on the sidewalk or at the park, and nobody will hassle you for it except for the beggars which always want a free puff. This removes the paranoia and need to stay locked indoors, and suddenly you see people walking around life with smiles on their faces everywhere. I smoke pot all day, and whenever I do I'm motivated to do something, because I'm happier with the Universe after I smoke and more inclined to interact with it.
Oh, and Muddy is 1000% wrong about smoking and driving. There's absolutely no correlation to it, it's an old wives tale. Pot smokers are less likely to get into accidents because they drive so slow. The only negative effect is getting people to put down the bong and move at traffic lights. Otherwise, I wish everybody would be high on the road, it would eliminate road rage.