As a child psychologist, it is important to understand what is appropriate for someone to do developmentally. And what is appropriate to encourage them to do. This doesn't end in adulthood. There are plenty of theories that explore developmental levels throughout adulthood. And therapists are encouraged to challenge people in their zones of proximal development (helping them grow into the next level, but not too many levels ahead).
I think the same is true of spirituality. While psychological development, particularly early on, corresponds closely to chronological age, spiritual development may not. There is definitely a correlation, but I have (anecdotally) found there is a wider range of developmental levels spiritually across age groups.
A very solid developmental model is Hagberg and Guelich's stages of faith, which I think does describe a lot of spiritual development. The idea of proximal development is critical in this model of stages of faith, as Hagberg and Guelich state that a person can somewhat comprehend the level immediate ahead of their current one, but not the further stages.
Therefore, if we try to push someone's spiritual development too far too fast, it simply won't work.
I also wonder if what many of us who push for various changes in the way church is done and theology is approached are doing a disservice to newer Christians. Frankly, most people who focus on these changes are not as focused on conversion, but rather existing Christians' spiritual development.
Perhaps the more rigid, information-driven, behavioral methods of spirituality are not only useful for some Christians, but necessary to lay a foundation. In many ways, this is what God did with the nation of Israel, creating a set of rather legalistic laws to create a foundation, later explaining that the law does not save anyone. As Paul stated in Romans 5:20-21, the law was given so that grace is more beautiful.
Just as little children need to know rigid rules about talking to strangers for their safety to later find there is appropriate ambiguity, perhaps rigid rules are appropriate for those who are young spiritually (even if they have been Christians for decades).
My appreciation of a devotional reading of Scripture is due to my prior reading for information. My love for transformation is accentuated because I have lived a life focused on sin reduction.
Remember the context of people's comments and their audience is important for me to remember. However, when a church only focuses on the more foundational elements, what happens when people are ready to move forward? How does one engage in zones of proximal development for a group of people with very different zones?