The purchasing agent for the government is not in the same position as the businessman choosing his own flight. For example, imagine that the government agent is buying a chair for a receptionist. If he buys a poorly designed chair, the worker who has to sit in it will suffer, or, if the chair is ugly, the worker may be unhappy. The purchaser has a responsibility to consider the needs of the employee who will use the tool or furniture. The taxpayer who ultimately foots the bill is also without the choice of selling his stock in the badly run government agency and cannot choose to boycott its shoddy products or to shop at a government that treats its employees better.
Tools have value for multiple reasons, and hedonistic qualities are not irrelevant. A businessman buying his own air ticket is buying his own tool, and different qualities may be important to different people. One may want the fastest travel time, another may want the softest seat, and another may want miles. The business has a vested interest in keeping its employees happy, so it gives those employees input into their own travel arrangements (a sort of fringe benefit). Within the parameters established by his employer, the business person is free to choose what best meets his own needs.