Because that is their issue and not mine. I pay them, not the exchange. Also IB customer support told me the problem was my end. That 15 min convo was very stressful whilst I am watching my account go down. It could have been spent better ways, but he gave me the wrong advice/help.
What you paid IB is commissions - the service to connect you to the exchange, not insurance premium that guarantee the exchange is working properly.
The exchange not working is your issue.