Anya,
There are no rose tinted spectacles on me!
You went to one match, I went to hundreds, so I think I have a better understanding of the level of 'violence' and threatening behaviour than you do! Shouting to opposing fans "I'll rip your f***in' head off if I get over there" sounds awful, but is just rivalry between fans. Many fans shout obscenities at the opposing fans/players, even the referee, it doesn't make them violent, it's part of the atmosphere!
Maybe if you'd chosen to attend more than one match, you would have discovered that for yourself!