Eh, the reality is that if something truly horrible happens, ad hoc courts will be sufficient. The huge problem with the ICC is that is a permanent, sitting court. And that means it is inevitably going to be sticking its nose into issue that are not deserving of that attention.
It's the same basic problem you have with government regulatory agencies. They exist to write regulations, so it should shock nobody that we're drowning in a sea of them. It's their job to write more.