Umhhh, the Rooney Rule was put in for a reason. The NFL had a pitiful record on hiring of minority HCs back then. In the 15 years since it was adopted, the NFL has made solid strides in minority hiring at the HC level, and the OC/DC levels as well. How much of that progress can be attributed to the Rooney Rule isn't clear, but it would be pretty absurd to assert none of it is. Most of corporate America has diversity directives in their hiring evaluation processes. The Rooney Rule is no different than those.
As for making "people" cynical on minority interviews, I think you mean "some people", not "people". Those people almost certainly thought that way before the Rooney Rule was implemented, so it's hardly surprising they still think that way now. Blaming the Rooney Rule is just another dimension for them to vent in...