I would not worry too much. We have stayed a few times per year for many years and have epxerienced most of the resorts.
We have never experienced a dirty room at WDW. Stains on carpets can and will happen in public places and cannto always be removed. there should not be fresh, wet, stains, but some discoloration or staining does happen from previous guests and hotels do not immediately change the room carpets but wait until the next renovation.
All we have ever had was a little wear and tear such as chipped corners, stain on carpet, etc. which just comes from so many using the room and needs to be expected in hotels.
If your room is not clean, just call housekeeping to come up.