What a depressingly stupid comment.
Firstly, this article is about the impact on the protagonists of taking part in a massively violent sport. It has nothing to do with fan violence, which is another issue altogether and simply isn't referenced in this article.
Secondly, fan violence in European and South American sports is massively overstated in the United States, and is broadly on a par with violence that takes place at any large gathering of people in those countries. You get more violence on an average Saturday night in a reasonably-sized English town than you do at, for example, an EPL match.
I regularly attend football matches at a lower level, and, although there are occasional violent incidents on and off the pitch, my level of apprehension is nothing like the level of apprehension I have going out for a drink on a weekend night in, for example, Colchester.
That's not something anyone can state with any certainty, regrettably. The only time that this specific subject has been put to the electoral test in the 1973 Sovereignty of Northern Ireland referendum , the nationalist/republican parties boycotted the process and exhorted their supporters to do likewise, with the result that the 99% vote in favour of remaining in the UK was somewhat discredited. There have been subsequent opinion polls which have suggested that there's no real appetite in Ireland, North or South, for large-scale constitutional change, particularly in Northern Ireland since the power-sharing Executive was put into place post-St Andrews, but this is not the same as saying that "a majority of X want or don't want Y."
What one can say with absolute certainty is that, for the duration of the armed conflict in Northern Ireland and to this day, the indigenous population of Northern Ireland who self-identify as "Irish," (an admittedly unwieldy description that someone with a more reductive approach to the conflict might reduce to "Catholics,") voted overwhelmingly for political parties who advocated the dissolution of Northern Ireland and reunification as a 32-County Republic.