Discussions about the spirit of the game are possible in situations that are not regulated by the rules or are regulated vaguely. Here, however, it is a precise application of a rule that has been in effect for many years, and everyone is aware of how it works.
Many games have been won using this strategy, and in a number of scenarios (for example, when the opponent has a large number of skeletons), it is necessary to rely on this rule as a matter of course.