Brexit is a very complicated matter, which is why many Britons find it altogether easier to adhere to an essentially uninformed position: either hard leave or hard remain. That is, after all, the choice that they were mistakenly offered in 2016.
It seems that almost everyone in the general public outside the media or Parliament wants one or the other, but Parliament as a whole wants neither. So it has fallen to our compromised PM to try and hack together a compromised version of the process that will somehow acknowledge and address the complexities of Britain leaving the EU, while the country looks on, confused, many still hoping that this bothersome elite project will fail so that their own emotionally / ideologically-pure version of Brexit or No-Brexit will ultimately prevail.
This was always more of an emotional matter than one in which facts could make any real headway, but Theresa May has been almost absurdly slow to communicate more widely the facts that informed her Chequers fudge. Consequently, the majority still seem to view her hard-worked set of compromises in the same way they view her compromised premiership - as doomed.