I think it was Ivy Beckwith who said that one of the reasons it's so hard to include all ages in a worship service is the didactic nature of our worship. The American Heritage Dictionary defines didactic as "intended to instruct" or "morally instructive." This approach requires attention to developmental differences.
What are the alternatives? Where is the ground that all ages share in worship? in the Word? Where is the ground that crosses generational, cultural, and sub-cultural differences? Where is that place where we encounter God individually? as a group? What do the scriptures say?