Likely you're exactly right. One of the hosts on a Sports-Talk radio station here in Chicago said a few weeks ago that Tebow was in fact being blackballed by NFL head coaches and front offices because they don't want the media circus that follows Tebow around.
Believed it then, I believe it now. (No, I'm not a Tebow fan or groupie by any stretch - but one does have to look at the situation objectively and ask why the guy isn't being picked up somewhere. Kurt Warner went through a similar problem after leaving the St. Louis Rams, although he eventually got picked up by the St. Louis Cardinals.)
Wooops! That should’ve been Arizona Cardinals. (Who were once in St. Louis, but I digress....)