here's a rule of thumb to go by.
if you're under 25 and listening to a hard rock/metal/punk band, then moshing is acceptable
if you're over 30, fat as a pig and listening to a POP BAND WITH A DARK PAST, then moshing doesn't make sense. Seriously, have you considered the irony of moshing to Bizarre Love Triangle?
There's a reason why people are upset at others barging in at the last minute and disrupting their evening. What we're seeing here is the physical divide between the "spotty students" and the "hooligans".
You are old, the band are basically miming to a preprogrammed set of mostly borderline gay dance anthems (despite you're claims to the contrary) and the other 20K in the audience don't find it necessary to push, shove and generally act like twats to enjoy the show. If you want moshing you should go see a band with actual energy playing agressive music. Moshing to New Order is absolutely ridiuculous. They are basically the Pet Shop Boys with guitars and worse lyrics.
enjoy!