I have hardwood floors in my kitchen and they do not go all the way under the cabinets. I discovered this when were were thinking of replacing the cabinets with cabinets on feet. We can't replace the cabinets without replacing the floor. So, If you are putting in new wood floors, I would suggest putting them under the cabinets...just in case. You never know what you might do in the future, or what a future homeowner might want to do. Although, I would imagine it would be difficult to putt out all the cabinets just for the sake of flooring under them...Just my 2 cents
If you are putting in a new floor and the cabinets are already installed, I don't know if I would take the time to take up the cabinets just to put the flooring under it. However, if the cabinets are not in yet, go ahead and put the flooring under them. It will be a lot easier than trying to fit the flooring around the cabinets.
