When choosing hardwood flooring for your kitchen, its important to pay attention to the species of wood. Woods like pine and cedar are probably not the best choices for kitchens as they are softer and less dense. Hardwoods like hickory, oak, maple and bamboo rank much higher on the Janka scale, which measures the resistance of a sample of wood to denting and wear.
Prefinished hardwood flooring has a much more durable finish than the finishes applied on-site. You can find factory-applied finishes with finish warranties of 25 years or more. That's NOT to say that on-site finishing isn't a good option. In both cases -- prefinished hardwood and hardwood finished on-site -- they can be refinished when wear shows.
Regardless of the type of hardwood floor finish, no finish will hold up to tracked in dirt and grit. Taking shoes off at the door will most definitely help preserve the life of your wood floors. If grit from the outdoors is left on the floor, it will act as sandpaper and scratch and wear down the finish. It is strongly recommended that you use walk-off mats at exterior entrances and non-skid throw rugs at high-wear areas inside the home, like the access doors and in front of the stove and sink.
Not many types of floor covering will hold up well to standing water and hardwood is no exception. If you have a liquid spill, clean it up immediately. Unless it's minor, expect that flooding as the result of a faulty appliance or ground water will most likely permanently damage your wood floor.
Hardwood has been used in kitchen applications for years and years. With proper care they are a practical and beautiful choice for kitchens that will last for years to come.