Why is it that dictatorship is a 'must' in a society without voting?
Democracy cannot exist without voting?
Lol... I beg to differ.
People think they live in a democracy today, whereas its nothing more than an illusion of one where the selected few govern everything and benefit the most.
Please attempt thinking outside the box for a moment and stop applying (highly flawed) cultural notions of our society (and the socioeconomic system) to the one of the Federation that is actually not supposed to be like ours.
For some people it comes down to the following:
'If its got no voting, then it MUST be a dictatorship'.
'If it has no money, it HAS to be Communism'.
These appear to be limited notions and projections onto society/system that was envisioned to be fundamentally different (just because the writers messed it up as time went on and degraded it into what we have today [even though its not] is their issue [stemming from the notion that they couldn't work within Roddenberry's rules).