Roots do work when the bar is "filled" and that's one of the biggest issues melee classes face. Roots are really long, they don't seem to fill Resolve up much if at all, and they can be used on you even if your bar is full.
Maybe I'm missing something but that seems broken to me.
Three seconds isn't that long and there is only one melee class Knights/warriors the rest are basically hybrids. Shadows have ranged attacks and methods to get out of roots. The longest root is 3 second so saying they last too long is a bit of misnomer.