As you mention it's all about the social media gratification for these idiots and younger people in wider society as a whole. Kids desperate for that 5 minutes of fame on Twitter, Tik Tok or Facebook. No consideration for fellow Wednesday fans or any poor sod unlucky enough to be on their train.
Similar thing with letting off pyros at half time on the concourses - sea of phones in the air with scarfs over their mouth cos they can't breathe!
Maybe I'm just too old now but I don't get it - surely there are better ways to create an atmosphere than extinguishing a train conductor?