I’d say that the idolisation of a fictional, ideal which society should strive towards but never achieve, allows focusing of opposition. If it weren’t for the gays/trans/gypsies/Muslims/immigrants/unemployed/trade unionists (delete as applicable) then society would be as it was used to be, which is always perfect and better than it is now. Of course as society will never be perfect, there must alway be a new group to blame for failure to meet the necessary ideal.