Around 135 the Gnostic Basilides composed a mighty treatise called the Exigetica which, judging from quotes by critics, contained lengthy exegesis on Gospel stories like the Sermon on the Mount and the Rich Man and Lazarus (M 78-9). We do not know if he was drawing on any actual Gospels, or oral tradition. Nevertheless, the attack was underway: whoever disagreed with him had to respond in kind, with their own texts, and somehow win the resulting propaganda war. For this purpose the New Testament was all but born. And in addition to this was the political need for a scapegoat: pressure against Christians by the Roman authorities prompted many to criticise other Christian sects with the general theme "they are the bad Christians, but we are the good ones, so you should punish them instead." Thus, pro-Roman elements, and the absence of anti-Roman features, were a precondition for the canonic texts of any church with a chance of success, and this also affected the formation of the surviving canon--and, incidentally, given the tense relations between Rome and the Jews, antisemitic features would also win Roman favor and release the Christians from Roman hostility toward Jews, although one could not take this pandering too far in a church largely comprised of Jews or their descendants.
In 144, Marcion proposed a reform of Christianity for which the church leaders expelled him merely for suggesting: that the OT was contradictory and barbaric and that the true Gospel was not at all Jewish, but that Jewish ideas had been imported into NT texts by interpolators, and only Paul's teachings are true. Moreover, he rejected the idea that Jesus was flesh, and the idea of Hell. But what is significant for us is that this implies a recognition of "texts" as being authoritative (M 90-4). Expelled, Marcion started his own church and was the first to clearly establish a canon, consisting of ten of the Epistles and one Gospel, which Tertullian decades later identified as the Gospel of Luke, though stripped of "unacceptable features" such as the nativity, OT references, etc. Yet Tertullian attacks Marcion for not having named the author of the book, but simply calling it "the Gospel" (Against Marcion 4.2), even though everyone had been doing just the same thing before him. Thus it is possible, if not likely, that by 144 the Gospel of Luke had not yet received its name. We have already seen how around 130 Papias perhaps names Mark so as to defend its authority, and alludes to a text by Matthew which could have inspired naming another Gospel after him, the one which seemed to rely most on OT prophecies. Thus, the very need to assert authority is perhaps compelling church leaders to give names to the Gospel authors sometime between 110 and 150, in order that the authority of certain Gospels can be established.