"a sickness born of unchallenged arrogance"? Yeeeesssht. My hyperbolometer just exploded
Like many football-related songs/chants/phrases, these things are said to a large extent to mock or wind-up opposition fans (and are obviously effective in doing so). Much like singing "what a ****ey home support" etc etc.
On the other hand, some Celtic fans would say eg Hearts fans are regarded as "mini-huns" not because they are closet Rangers fans but because their behaviour is thought, rightly or wrongly, to be similar (in the sense that both are very strongly anti-Celtic and perceived by some to be anti-Irish/catholic). I tend to regard the stereotyping of any group of fans to be as least as likely to reflect one's own prejudices as reflect genuine features of that group.