The problem is people in general, across demographics, are dumb and irrational as a collective. Generalisations are often accurate but there are always exceptions. The one surety is that people who are members of the collectives always think the generalisation doesn't apply to them.
My position wasn't that people didn't understand politics, but they failed to understand the economic implications, which is a different argument. It applies across the demographics but to different things. For the young, it's tuition fees, for the middle, it is often immigration, and for the elderly, social care is the key blind spot. Brexit is a mess across the generations.