I mean, 73% of the 18-24 and 62% of the 25-34 voted remain, whereas 60% of the 55+ voted leave. Statistically, it's a pretty valid point.
I haven't done the math, so I won't make assumptions, but I would bet the percentages from the polls roughly match up with the actual results from the referendum
> Also did they vote remain because it's cool or did they actually have some other reason?
That's an entirely different point, you're just moving the goalposts now. The question isn't whether young people were justified in voting remain, the question is did they vote remain.