Good lighting is not a luxury in a professional shop, it is a safety requirement. Working under a vehicle or inside an engine bay with poor visibility slows you down, causes mistakes, and creates hazards that better lighting would have prevented entirely. Fluorescent work lights give you broad, even illumination that reaches into the areas where you actually need to see clearly, without the heat and glare that other light sources bring into a confined workspace.
Whether you are hanging a light over an open hood, running one along the underside of a vehicle, or lighting up a dark corner of the shop, a quality fluorescent work light makes the difference between squinting at your work and seeing exactly what you are doing.