It's the problem when you have been spoilt with success, you become tainted. Arsenal have been spoilt by Wenger and United spoilt under Ferguson. Most of their fans don't know anything else and have only supported them in this era.
I doubt many United fans have experienced the dark days of the 70s and waiting 26 years for a league title or if Arsenal fans witnessed the boring football under George Graham and how dire they were for a good decade before winning the double in 71 because if they did they would be more empathetic and be able to relate to fans of normal clubs that have had ups and downs.
The media have convinced everybody that the elite are entitled to things everybody else isn't. That comes from the right wing press in all forms of life. From the expenses scandal, banking crisis to the fact Liverpool and United are entitled to be at the top and nobody else should be able to challenge that authority. People don't like change in any aspect of life and that is why Chelsea and City may not be respected, but they are feared and the two can be intertwined anyway IMO.
Some of the most intelligent footballing conversations I've had in real life and on forums have been from fans of West Ham, Man City, Fulham and Wolves who tend to have a broader view and perspective on football than Arsenal or Spurs fans who display a lot of hypocrisy and in general are too narrow minded with posters like Ammar proving an exception. However Older Liverpool and in particular older United fans are brilliant to talk to and amongst the most knowledgable you can find, sadly due to success they've attracted a lot of plastics who know little about the game so are harder to find, same will happen with us soon and City.