Although we use the generic term 'rags', there is a difference in rags(plastics) and proper reds, most will want us to win the league. I have friends and family who are United fans and several of them go to games. We share banter and take the piss but that's all. Reds who know their club and know what they are talking about I am ok with, as they know enough about our history to not insult me on calling us a plastic club having no history.
Rags on the other hand know next to fuck all a out their club and it's history nevermind ours. I have met many rags who try and give it out. They don't last long with me as I don't tolerate rag fools gladly.
History and memories are important and as we get older we tend to remember them with affection or in a different light to at the time its the realisation of mortality coming to the fore.
Its also important to know that success is relative and isn't necessarily defined by history.
The Pats have little history in time compared to many other NFL teams but are the most successful in its history.