The Second Vatican Council stated that the goal of the Church's ecumenical STRATEGY was the UNITY of ALL Christian churches through COMMUNION with the Roman Catholic Church:
"The results will be that, little by little, as the obstacles to perfefct ecclesiastical communion are OVERCOME, all Christians will be gathered, in a COMMON CELEBRATION of THE EUCHARIST, into the UNITY of the ONE AND ONLY CHURCH, which Christ bestowed on his Church from the beginning. This unity, we believe, subsists in the Catholic Church as something she can NEVER LOSE, and we hope that it will continue to INCREASE until the end of time." - Second Vatican Council, "Decree on Ecumenism," no. 4.
People who have been truly regenerated and converted through the preaching of the Gospel tend to want to tell others about what God has done for them. Is that surprising? They have believed and God has saved them through the simplicity of the Gospel of Grace alone, through Faith alone, in Christ alone.
The remedy for the shallowness of some of these Babes in Christ is the strong meat of the Word of God that requires hard work, not formal institutions that wear the same clothes.
If Rome and the other main stream protestant churches would teach the True Good news, they would stop hemorrhaging members and start making the tares uncomfortable.