Why anyone in football would not want to remember Munich is beyond me. The small minority of City fans who mock the disaster manage to forget Frank Swift's death in the crash. Likewise those England fans (again a minority) who are anti-United seem to ignore that there were England players who perished that day.
They weren't murderers, or paedophiles, or criminals. They were talented young footballers, many of whom played for their country as well as their club. If people don't feel the need to publicly demonstrate their sadness at the crash then that's fair enough. However, there's a difference between that and being deliberately disrespectful.
Also, if you have a minutes applause because you're worried there'll be boos, then the people who boo have won...