Why was Scotland's vaccine passport expansion dropped?

Key Facts

Take for example the Chambers of Commerce, who said they could be convinced to back expansion if there was "clear" evidence in favour of it - but who ultimately said they were "unconvinced at this time that the public health benefits outweigh the negatives for individuals, businesses and the economy".
The factors cited time and again were concerns about implementation costs - particularly at venues which do not normally need to employ door staff - and the timing, with many businesses banking on a strong festive period to help them bounce back from the damage of lockdown.
The Scottish Greens were originally critical of vaccine passports, but were convinced of their merits shortly after signing up to a cooperation agreement with the SNP and joining the government.
The Greens backed the government on vaccine passports when case numbers were rising It is unlikely that this is a topic which could have sparked a full-scale Green revolt of course, as a move to vote against the government on vaccine passports would have seen their partnership fall apart just as everyone is getting their feet under the table.