Throughout the day there was, no doubt, and exchange of ideas and questions put forward as Paul spoke to the Jewish assembly at his residence in Rome (Acts 28:23, 30). The problem was that some believed, but, evidently, most did not (Acts 28:24), which was characteristic of the Jewish response throughout Paul’s ministry (Acts 13:45, 48; 14:4; 17:4-5; 18:6-8; 19:8-9). So, I don’t believe the ending in Rome came as a surprise to Paul.
We should not interpret, however, that Paul’s quotation of Isaiah in Acts 28:26-27 as God’s rejection of the Jews and his turning to the gentiles to take their place. This is not what Paul (or Luke) intends for us to understand, for even though the Christian church is mostly gentile, neither have the gentiles (as a whole) accepted Jesus as Lord. But, concerning the Jews, Paul clearly tells us in his letter to the Romans that God has not rejected his people, the Jews (Romans 11:1-2). Their response to the Gospel does not change God response to them. On the contrary, Paul testifies that the fall of the Jews became the riches of the nations (Romans 11:12). Then he argues, if their fall is so valuable to the world, how valuable will be their return to God’s grace be (Romans 11:12) and then answers his own question in Romans 11:15, showing that their reconciliation will result in the resurrection of mankind.
Paul’s quotation of Isaiah 6:9-10 in Romans 28:26-27 is a variation from the Septuagint rather than the Masoretic text (Hebrew rendering). The Hebrew uses the imperative tense in Isaiah 6:10 while the LXX uses the aorist tense. The result is “the blame for Israel’s estrangement from God is placed upon the stubbornness of the people themselves.” Moreover, the Septuagint rendering expresses a more hopeful account, showing that if the people did repent and turn that God would also return and heal them.
The problem reminds me of an incident in one of my favorite movies, the Shawshank Redemption. In it the main character, Andy Dufresne, who is unjustly serving time in prison for a murder he didn’t commit, has finally found proof of his innocence. He tries to explain it all to a corrupt Warden Norton, asking him to submit the proof to the proper authorities. Andy’s words fall upon deaf ears, so he asks: “How can you be so obtuse? …Is it deliberate?”
The Jewish plight in Acts and their response to the Gospel seems very similar to the warden’s attitude with Andy. Just as Warden Norton had his own agenda that didn’t involve freeing Andy, so the Jews—especially the Jewish authorities of the 1st century CE—had their own agenda. They had a hope to be free, and they looked for a messiah who would free them from their enemies, which in the 1st century was Rome. Paul’s message of Jesus fulfilling the Messianic office by conquering the hearts of Jews and gentiles alike didn’t fit into this Jewish 1st century hope. Rather, the Jews of that day had their eyes upon a hope for freedom from their present unwelcome circumstance, not upon the fulfillment of the hope of eternal freedom. They looked upon the gentile presence as something unwanted, but God had placed their little country between two great gentile empires, whose communication and trade went through Jewish lands. The Isaiah commission of the Jews to take the Gospel to the nations (Isaiah 49:3, 6) which ultimately embraces all men as brethren, was a very unwelcome thought for Jews under the oppressive Roman rule in the 1st century CE.
 Witherington; The Acts of the Apostles; page 804, citing Longenecker, Acts, page 571.