This is a good moral question. My impression is that some people today, especially here on HN, feel very uncomfortable taking
any moral stance and instead have a worldview that says what is right is determined entirely by what the market produces. Basically capitalism is God.
I like capitalism, but I view it as a means to an end, not an end in itself. Instead of evaluating our moral against what capitalism produces, we should evaluate capitalism by how well it supports our morals.
From that perspective, yeah, I think it is kind of bad. If we are placing a high tax on cigarettes because our society has made a moral choice that cigarettes are bad and people who smoke are bad, then I think that moral choice should apply equally to all people regardless of wealth. My moral code states that power does not excuse sins.
On the other hand, if the tax is a pragmatic one to, say, help pay for universal healthcare and offset the higher medical costs incurred by smokers, then the tax is a reasonable approach.
In reality, the tax/law is probably a combination of the two goals, which is why I think a tax is kind of bad but kind of OK.