Possible Explanation for Late Reception of the Gospels by Early Church in Rome (Gupta)

As I prep for new courses here at George Fox Evangelical Seminary, I am enjoying getting more acquainted with gospels-scholarship (I am teaching “Gospels and Acts” this term). I found this statement from Eugene Boring (An Introduction to the New Testament) fascinating. 

There is no indication that the Christian community in Rome, during the period when it was becoming the leading church in the empire, accepted the Gospels into their collection of normative Christian documents until well into the second century. One reason for the hesitant reception of the Gospels is that the reading of narratives of Jesus’ life and teaching did not already have the accepted slot in Christian worship that had become standard by virtue of reading the Pauline letters and other letters in the Pauline tradition alongside the Scriptures. It is likely that another, theological reason played a role as well: narratives focused on a miracle-working, divine man Jesus were too easily misunderstood in docetic terms, and difficult to reconcile with the epistolary focus on the cross and resurrection. (p. 507).

Is Boring right about this? What do you think?