This sort of reasoning, which places the blame for apostasy on supposed moral shortcomings of apostates, is a satisfying one for those still in the fold. It reassures them they are right to keep believing, and that there are no legitimate reasons to stop.
However, it’s untrue. People are leaving because they have doubts about the credibility of Christianity’s foundational claims. Before the internet it was hard to research those claims. Now, anybody can do so at the touch of a button. The church no longer can control access to that information.
So long as those still with the church continue to cling to these wrong but reassuring rationales for why apostasy is increasing, it will only continue to increase, because you’re not plugging the hole.
You’re sticking your thumb where you think the hole is, when it’s somewhere else; people have doubts. Those doubts are well founded and the church makes little or no effort to address those doubts, instead sweeping them under the rug and advising the faithful not to have those kinds of thoughts or research the matter online.
As an aside: Suppose for a minute there’s a group traveling about your area, led by a charismatic speaker who claims the world is ending soon. He promises he alone can save you, but only if you sell your belongings, devote the rest of your life to him, and cut off family members who try to stop you.
He may also want to change your name, assign you a new identity, advises you to leave your home/job if necessary to follow him, and says that if you don’t love him more than your own family then you’re not worthy of him. His followers wrote a book about him in which he performs many miraculous feats, but no contemporaneous outside source corroborates their claims. What sort of group is that?