This piece by Keener is golden. I'll just highlight a few points.
Some writers have expressed the conviction that any legitimate interpretation of a passage should already appear in the church fathers, and questioned any interpretation that does not.
On many issues, there was no universal patristic view, and everyone who studies the church fathers recognizes that they often differed among themselves. For example, many early interpreters, such as Papias, appear to have been premillennial. By the time of Eusebius, however, premillennialists were viewed as schismatics; amillennialism prevailed by this period.
Second, their ancient setting was not always the decisive advantage we wish it to be, since it was not the same as the settings in which the biblical books were written. For some examples: whereas the Hebrew Bible addresses various ancient Near Eastern settings and the New Testament presupposes a Jewish context (most thoroughly in the Gospels and Revelation), only a few of the church fathers (such as Jerome) knew the Jewish context well. Many, in fact, were unfortunately decisively anti-Jewish (including Chrysostom, otherwise one of my favorite commentators).
Likewise, even Greek culture changed. Stoicism was the dominant philosophy for the milieu addressed in Paul’s letters, but Platonism dominated the patristic period. Most church fathers wrote after the second sophistic, a different rhetorical situation than prevailed among the biblical writers. (Indeed, some of the best-known church fathers were more homileticians than exegetes, their homilies marked by efforts to communicate in their context and not just explaining texts’ meanings.)
Once some Fathers used biblical texts polemically against Gnostics or Manicheans, sometimes in understandable ways in their settings, subsequent interpreters sometimes applied these texts only to these settings, as if these were the texts’ original settings.