1Th 2:12 that you should walk worthy of God, who has called you to His kingdom and glory.
Sure, they were still seeking an earthly kingdom. The Holy Spirit had not fallen on them to bring them to understand that the kingdom is not of this world. It wasn't a dumb question because they didn't understand.
Jesus had just spent 40 days with them speaking with them about the Kingdom that he was going to restore to Israel. They weren't discussing needlepoint. He was telling them what the Kingdom would be like when restored to Israel. And by the way they already had the Holy Spirit [John 20:22] And Luke is quite clear. And they understood his words quite clearly.
BTW Where will the Kingdom of the New Jerusalem come from? And where will it come to?