One of the factors/examples that can negatively affect online reviews from users of vacation rentals is the inability of users to use the pool, even though the vacation home was advertised as having a pool. Another factor is that users cannot use the pool due to lack of proper cleaning.
There is a possibility that the pool equipment may break down unexpectedly. However, it can also break down due to lack of proper maintenance during the period when the pool is not in use.
In some cases, it is not due to malfunction, but due to lack of cleaning, which makes the pool unsanitary and unusable.
In either case, this can be one of the major reasons for a poor rating in online reviews.