Yes! It is helpful to fully understand the meaning of the word cult to know why.
1. a system of religious worship or ritual
2. a quasi-religious group, often living in a colony, with a charismatic leader who indoctrinates members with unorthodox or extremist views, practices, or beliefs
1. devoted attachment to, or extravagant admiration for, a person, principle, or lifestyle, esp. when regarded as a fad i.e. the cult of nudism
2. the object of such attachment
3. a group of followers; sect
Is Amway a religion? Yes it is.
re·li·gion (ri lij′ən)
* expression of such a belief in conduct and ritual
* any object of conscientious regard and pursuit
Amway and many other Network Marketing/ MLM companies teach you to separate from outsiders who are negative towards your efforts. They teach you that those who do not agree with your business choice, are simply "close minded."
There are many other examples of why many would call Amway a cult. You can find some great examples at
Most importantly do not show animosity towards your wife. Continue to show love and support. Concern is great. It is good to take the time to discuss concern. Do not openly attack her and what she is doing. Most people in a traditional network marketing or mlm business are used to attack and are always on the defensive. If you can have a conversation without attack and express concern without control, your efforts will not go unnoticed.
I hope this has been helpful.