1. To be fair, (I assume) most of the posts on Justin Bieber forums are from people that are not of voting age.
2. People think of them as 'ignorant twits' because they don't realize that by ignoring such things decisions that affect them are being made for them. It's too easy to find yourself in a situation you don't like because you were too busy ignoring what was going on to realize what was happening. E.g.:
“There’s no point in acting all surprised about it. All
the planning charts and demolition orders have been on
display in your local planning department on Alpha Centauri
for fifty of your Earth years, so you’ve had plenty of time
to lodge any formal complaint and it’s far too late to
start making a fuss about it now.”
2. People think of them as 'ignorant twits' because they don't realize that by ignoring such things decisions that affect them are being made for them. It's too easy to find yourself in a situation you don't like because you were too busy ignoring what was going on to realize what was happening. E.g.: