Even if one's anger or frustration is justified that doesn't make it ok to scream abuse at strangers or burn down the neighbourhood. Politics is not some internet poll where the worst thing that could happen from voting for Boaty McBoatface is some international snickering. Brexit will affect generations to come, and the nasty anti-immigrant rhetoric has cost an MP her life. If Trump wins in the USA, it is potentially a serious threat to that country's democracy. "Burn it all down" is not an acceptable solution in a civilized society. Even historical revolutions that ended up largely as just futilely burning it all down (e.g. French Revolution) at least started with an actual vision for the future and specific demands they wanted met.
PS I just watched the same thing and I thought they were reasonably fair, it was clear they are voting against Hillary rather than voting for Trump, though it was unclear why they think Hillary is so bad and I was disappointed Jessica didn't do any follow-up about that. The few people I've argued the merits of Hillary with were very similar to the pro-Leavers I argued with, in that they have very few specifics to offer as proof of Hillary/EU being worse than the alternative, just a general sense of distrust.
PPS the few articles I've seen written about trolls make it seem as though trolls are an expression of deep seated frustration, anger and general unhappiness which finds solace in making others feel the same way.