Voting for a leader is voting for someone to have authority over us; perhaps someone cleverer, more experienced, more capable and better able to make decisions. Yet many of us have clear and often opposite views to our leaders, who are also apt to disagree amongst themselves.
It may be that our need to be lead by capable people is more a fear of other members of our society, who oppose our sacrosanct views and values... lets call them idiots (these people have as many rights and as much democratic authority as ourselves). After all, we can aspire to become that sensible authority figure in parliament and the self evident fallacy of the views of those other citizens (idiots) precludes them from sharing the same success.
Put another way: We may prefer the current model of Parliamentary Democracy to Interactive Democracy because we would rather have decisions made for us than share equal power with the idiots in our society!
However, this argument ignores the prospect that a well explained argument can win over the stupidest and most dogmatic of our fellow idiots.