One needs to read all of chapter 23 to see that the group of people that Jesus is speaking to is the pharisees. In fact every verse of the chapter is an admonishment to the pharisees in regards to their hypocracy and their leading of the Jewish nation astray.
In addressing Jerusalem Jesus is addressing the pharisees - just as he does in all of chapter 23. Jesus longs to gather the children together - who are the Jewish nation under the leadership of the pharisees. And it is not the children who are not willing - though that is what chesternrules wants us to think. Verse 23 specifically says the pharisees were not willing to let God gather the children together. The verse isn't even in reference to freewill - but the effort of the leadership to withhold the truth of the gospel from the children of Israel.
