It has just become some kind of sacred cow that we are made to worship. The government explicitly asked for the referendum to be advisory,it is therefore non binding anyway.
The Tories have jumped on it because they see it as an opportunity to neutralise the fractious question of Europe, which has been a thorn in their sides and source of party division for decades, once and for all. In framing it as upholding democracy rather than political opportunism, they have effectively castrated anybody who would argue against Brexit for fear of being labelled as undemocratic and going against the wishes of the electorate. This is why every politician that talks about Brexit starts off by saying " of course we are leaving the EU" and " of course the result of the referendum must be respected" before going on to say what a bad idea it is.
This to me is a dereliction of duty and a cowardly betrayal of the futures of our children for party political purposes rather than acting on what is best for the future of the country.