There is a disconnect in much of the fashion industry between functional work wear and fashionable clothing items. Work wear must be durable, practical, and fit safely and well in order to provide needed protection. Fashion wear must look memorable, fit well, and stand out enough that others will want to emulate the trend. There have been a few companies who attempt to cross the bridge between the two needs, but it has not always been successful.
One of the hallmarks of good work wear it its durability. Wearers of this clothing are not walking runways, but are finding themselves crammed tightly into small spaces, kneeling and bending, and rubbing the clothes against things as they work. Fashion clothes that look like work wear are often not designed to take this kind of regular use, and this detract from their appeal. Most workers need a pair of overalls that will last them years, not one fashion season.
The location of pockets, padding, and extra seams are well planned into work wear. Fashion companies who try and emulate this need to understand the technical reasoning for these supports, and to go with them. To get a pair of carpenter pants with a hammer loop or pocket in a strange position does little good for those who are actually putting hammers into them.
The Sweet Spot
There are a few companies that have come from the work wear side of things and been able to create fashionable trends. Most notably, Dickies, who designs well-crafted work wear, has designed clothing that is fashionable to skateboarders and snowboarders, and durable enough that they can achieve the look they want with a pair of pants that will stand up to regular athletic use.