I can answer this a bit...though not from a RCC perspective.
We have had several people come to attend and join our (SBC) Church recently from a mainline methodist church that has gradually ceased teaching the gospel. They come because they can no longer agree. One of those people told me that there are a few older people still there who agree with the problem, but because of loyalty to the church and the people at the church, have decided to stay and hope, and/or work for, a turn-around.
Now, if myself and our current senior pastor started preaching this weekend that Jesus loves everyone and that all will be saved regardless of their beliefs, and that no one really need to turn away from any sin they might be involved in, or turn to Jesus...Some people would leave, for very good and godly reasons...some would stay, because they agreed with us (wrongly), and i suspect some others would stay because they are so invested in the church after having spent their lives here, that their loyalty to the church and the fellow members would compel them to stay (also a good, godly reason). They would stay, knowing we were teaching wrong ideas, but hoping we would come around, or that the next pastor would be more biblical.