Players use utility if it's expected of them. If your PLD and BRD have to take turns silencing High Voltage and your BRD misses the silence, then everyone knows who is responsible. So you get it right. If you give everyone a silence, then it falls to the lower end of the dps spectrum (tanks and healers) to sort it out so that everyone else can tunnel on the boss. If missing the silence doesn't have consequences, then nobody will do it.