Because, (if i'm reading it right, you are talking about a second referendum) pretty much every media outlet has shoved this rhetoric down our throats that a second referendum would be unacceptably anti-democratic, quoting multiple leave commentators claiming we've already had one, and that it only seeks to overturn 'the will of the people'.
i don't see how being asked again is in any way undemocratic. it has been over three years, and whether outright lied to, or simply believing unfounded assumptions with best intent, so much has become (or should be) so much clearer, that surely the direction now evident is worth asking again.
There was a referendum in 1975 which overwhelmingly (properly overwhelmingly) determined that the UK should be part of the EU, so by its own logic, this brexit referendum was therefore wholly undemocratic as it seeks to overturn the decision of that referendum.
A second/confirmatory referendum does increasingly seem the only way out of this mess, with or without a GE.
imho.