If you go for the taxation route it affects everything, including pubs which are having a rough time of it already.
The objective is to reduce the incidence of people getting smashed before they even leave the house and then going out to drink even more.
What this won't have any serious impact on is people drinking wine or spirits at home, it's mainly going to affect beer/lager and cider, particularly at the cheaper end of the market. One could argue that minimum pricing disproportionately targets those with low incomes and the unemployed without any significant impact on the increasing risks being posed by alcohol consumption by the middle class who are increasingly drinking at home.
A minimum price would have little or no impact on pubs (unless they use it as an opportunity to raise prices) while going after the cheapest booze in supermarkets which is where a large part of the problem arises. In principle I don't have any problem with that but I don't drink at home so it would have naff all impact on me anyway.
I also note that the Tories, Lib Dems and Labour were all opposed to the idea of minimum pricing when the Scottish government originally proposed it.
Can't beat a bit of opportunism can you especially when it also temporarily diverts attention for you cash grab budget the day before.