Jesus' teaching is often both too rich and too nuanced to describe its tone well in just a word or two. In addition, he's so very good at addressing the particular heart issues of particular listeners that he'll often switch his tone from one listener to another. In John 6, we have both very meaty material and multiple groups of listeners (the crowd, the Jews, the disciples), so that I'm hard pressed to summarize Jesus' attitude succinctly.
I do think verse 15 is key to the dynamic between him and the crowd. They've decided to make him their king by force. That is, they're more interested in using him to help with their plan than they are in getting on board with his plan. Given this, he seems incredibly patient to me, while at the same time absolutely adamant that understanding and following his agenda rather than theirs is critical. There's no compromise or second-best idea entertained. He's blunt and uncompromising, yet continues graciously to teach.
How's that for a start? I too am interested in the question. Other thoughts?
