Not to be a debbie downer, but here are a few reasons and I will just touch on 2 glaringly obvious ones:
1) Because it is much more likely than not that these big money people and people within the AD, who got their money or their position from being good business people, don't typically like to leak a great deal of information about what is going on. In business and in public administration, leaks can be deadly. Most of these guys know when to keep their mouth shut and probably don't go telling a great many people (especially the friend of a friend of a friend) what the real scoop is.
2) because we (the fans) are shooting down any idea but Gruden, even if there was a tiny leak or a whisper, we wouldn't even consider it because our minds are made up. This is the part that scares me the most about all of this. We cannot get good information from both sides of the isle because we tend to run people off who have information we don't like and we also tend to give too much credence to people whom we don't know who give us information that we want to hear.
That is just all hypothetical of course. I want Gruden too, but some of the reasons that we chose to support the idea that Gruden is coming could just as easily be used to surmise that he isn't.
My fingers are crossed, but when I read these boards and see the information that everyone latches on to I get more and more confused as to why people seem so convinced.