I agree, not talking about any "super fan" nonsense, it's fairly obvious there are people who just don't join in with various chants other than OWTS, come on you reds or (randomly) the Virgil Van Dijk one.
What doesn't help is that that vast majority of people usually only sing one "round" and then give up. Keep the chant going ffs. Second half away to Arnhem with the Wanyama chant going for half an hour sounded epic.