Casual dating is an acceptable way to go out with someone in many societies, but it is not expected to lead to marriage or a long term relationship. People who get into these types of arrangements are told in the beginning that there will be no future, and they must agree to the terms. If they state that they might change their mind in the future, they are often dumped quickly by the person who is not interested in forming a committed relationship.
There are many times when a person has just gotten out of a long relationship that did not end well, and they are generally the ones who state they would rather not make any commitments. Their stated goal is to just enjoy their own pleasures, and they will let the other person know that their needs come second. This type of arrangement works well for them until the other person tires of being used, and they might find they missed an opportunity for a lifetime of love.