You do not sound childish and you have every right to vent. I also find it a bit strange that they would feel the need to put that information in your letter. One of my German professors told me that the DAAD has had to make budget cuts recently. I haven't had a chance to do more research on this, but perhaps they had fewer grants to award this year.
Just make sure to turn whatever feelings you are experiencing right now into something positive... and prove to them and to yourself that if there is a will, there is a way! By the way, that sounds like an amazing project proposal! I would love to see that on the stage. And don't give up on Fulbright yet! We'll be crossing our fingers (or for the German speakers out there: pressing our thumbs) for you!