Iskcon is a Group of a people.
In Kalayuga , Where Bhakti is not encouraged by Mayadevi…Its tested regularly . When a person lands up in Iskcon , he has to talk a devotee or Say “ A human being”. So its a classic case of Patients treating a new patient. So a person who is also trying to grow spiritually , is also trying to encourage others to grow spiritually.
Now, Challenge is that …Every such devotee is not expected to be a leader or a preacher.. Still every does preach ( within limits of his knowledge or purity)..But his intention is pure…
So , every such teaching can be good or low in quality… Iskcon has nothing to do with it… You need not grow in attachment with Lord Krishna by going through Iskcon only…. Challenge is “ Not loosing focus” , not to get discouraged… USe your mind as well, Pray to Krishna that your bhakti does not get discontinued due to any perception , myth or truth…
Mayadevi also works hard to spread any perception so you forget Krishna..
p.s. Even I dont go to Iskcon often… But have complete faith in Bhagwad Gita and Prabhupada….
The above is my answer to a Query on Quora