Thousands of guests have thousands of preferences. Some don't care about the floor, but some do:
- some prefer ground floor
- some like view from above
- some are afraid of thieves that may step into window/balcony
- some don't like to climb up stairs if there is no elevator
- for some climbing is acceptable up to some level
- some like sunlight until the sunset, and don't like to be shaded too early
- some like / don't like number X and want exclusively / to avoid this particular floor
- ... and numerous other preferences for whatever reason!
As you can never imagine what ideas they may have, it doesn't cost anything to give this detail in the description. If it is not of particular importance, they will ignore it, but in the case it is - they will be grateful!