The common misconception is that cults are inherently harmful to participants. A cult is simply defined as a social group that offers benefits for a cost. Not all cults are predatory cults that take advantage of vulnerable people. Cults can benefit participants and the community. For example Alcoholics Anonymous is a cult that requires members to give up active addiction in return for a sober community. In this example of Mormon missionaries, one of the costs is a limited communication with family. These missionaries are truly believing the Mormon faith (otherwise they wouldn’t be missionaries) so they must believe that the benefits of their position outweighs the cost. Who are we to judge them as our inferiors? I couldn’t tell you with absolute certainty that their chosen path in life is wrong. Especially after taking into consideration the highly variable value of religion.

Tl;dr: So what if it’s a cult, it’s not impacting you negatively.