We, and I believe 99% of the hotels who work with booking.com, are having an strange issue with guest mentality: many people evidently dont read trough the amenities and services which hotel is providing. Then they publish angry reviews and low rating marks simply because hotel or B&B hadn't provide certain amenity, service or facility, which guests for some reason expected, even though it is often very clearly listed in the description that this particular amenity isn't available, or is available only for certain, higher rate.
There is also similar aspect about guests angrily complaining in the comments (or at the place) about certain fees and deposits, even if they are listed at the invoices and description.
Most common complaints of this kind are
1. Complaining about no TV, after booking cheap rate room without TV-which is clearly listed (very often in our B&B)
2. Complaining about surcharge for the pets, disregard if this is clearly listed at the property description(often with us)
3. Complaining about room having no private toilet and shower, after booking cheap rooms without toilets.(we have wc in all rooms, bt may hotels who have both rooms with private toilet, and rooms with public wc for cheaper price face this type of criticism often)
4. Complaining about security deposits even though it is clearly listed in the conditions.
5. Demanding 5 start hotel amenities like fitness-room or jacuzzi in 2 star hotel.
6. Complaining about hostel being a hostel
Any idea how you are dealing with it?