another problem in people's minds is evangelism.
'why share the gospel with people whose fate is to reject it?' -- is the criticism, usually phrased a bit differently, admittedly..
for one thing, God chose the foolishness of preaching. another thing is the purpose of evangelism: is it to win souls or is it to find lost sheep? if man is totally unable to respond, then doing the work of an evangelist does not have as its goal one man convincing another to do something that he is unable to do. if this must be the work of the Father through the Spirit, then the evangelist is only facilitating the work of God by bringing the one thing that is missing: the word of God, which magnifies Christ. the purpose of an evangelist is to praise Jesus Christ in the hearing of people - and when He is lifted up, His sheep hear His voice.
so total inability leads to that the purpose of evangelism is to praise the Lord - not to convince, coerce, persuade, argue into, move, seduce or otherwise to 'win' souls; that is God's own work. the gospel of Christ preached is a call to His people and a condemnation to the Devil and his children, which we once were, but the Word entered into us and changed us.
so why share the gospel if it falls on deaf ears? because it praises God, and through it God calls His own to Himself. that people who believe this doctrine aren't interested in 'missions' or don't believe in evangelizing is a myth, and here is justification for it on the basis of total inability