Bill,
When Christ taught the parable of the sower, He taught that there would be those who would not stay planted with the good seed of the gospel, even though they might have received it. He taught the same concept in talking about the sheep and the goats. He taught it about people who would build their “house” upon a sandy foundation, rather than upon a rock-solid foundation.
Of course people will be human, especially when taught with the concept that free agency is absolutely paramount. No force, no coercion, no fear factor to keep people in the church.
Just because people have their agency and choose something different for themselves than what the covenant gospel teaches, does not mean (1) that they are “bad” people or will “go to eternal punishment”, nor (2) that the church they left was a wrong path. People have all sorts of reasons for making the decisions they make in life. They want what they want, and choose based on what they want, including some choosing to “start their own church” or to follow some appealing belief or leader. So what’s new with that? Nothing.