The government engaging in social engineering (taxation to change behaviour, for example) interferes too greatly with free enterprise and the freedom of people to seek the kind of life they want without government interference.
The moment a government does this, they are trying to alter people to force them to be like a certain group, regardless of whether or not that group is infringing on anyone else's rights.
If they do it with one thing, what is to stop them from doing it with anything else? Flipped around, what if they decided that, by a majority rule, they wanted to socially engineer us back to the values of the early 1900s?
Surrenders moral, intellectual and economic control over individual decision making to social planners, economic planners, and controlling special interest groups. In a democracy, mindless masses are created and shaped into public opinion by propagandists to promote their own social, political or economic or even at times military agenda as public policy.