Why should Jeremy Corbyn go to the CBI conference?

So Jeremy Corbyn is not going to attend an "important" conference hosted by the CBI - why should the leader of the Labour Party who opposes much of what the CBI stands for attend such an event? Why should Corbyn, who is leading the opposition in Parliament to the unjust Trade Union Bill - backed wholeheartedly by the CBI - attend their conference in order to exchange pleasantries and thereby convey some sort of legitimacy on that organisation's stance on workplace matters?