Re: "the opportunities created by Brexit".
Given that the Supreme Court confirmed parliament's right to scrutinise any deal, it was the government's fault for not involving parliament earlier. Just like it was applying to leave without having worked out a strategy.
Parliament has not ignored the result of the referendum. But the result was also never a piece of policy, let alone legislation. For example, the referendum never said whether the UK should stay in a free trade area with EU or in a customs union, it was also silent over the UK-Ireland border, although it has already agreed by treaty to avoid one. Difficult to do once this becomes an external border.
Parliament and the government have to decide how best to interpret the referendum, including what kind of relationship it should pursue with the EU. People hate such details, which is why catchy, populists slogans are so effective. Strange thing is, however, catchy, populist slogans don't solve problems either.