Infinite allows you to use material -- particularly IP -- that is not released under any license. This restriction is intended to protect their IP from getting accidentally released under the licenses. Surely you can't begrudge Paizo of wanting to protect the stories, characters and worlds they have created, especially in light of how much material they have otherwise made available?
If you want to create something using ORC, just use ORC. If you want to use Paizo's IP, you have to make concessions.