If we put taxes on things that can lead to offenses and problems with health such as alcohol and cigarettes and other tobacco products, then in a sense we are saying that we would rather you not use them but that if you do there is going to be an extra cost.
It is, in fact, immoral for a government to decide that certain consensual adult activities should be penalized through excise taxes. In effect, it penalizes people unfairly for choices that they as free human beings should be able to make without government interference, and the money from such taxes is undoubtedly squandered in the end anyway.
Excise taxes should be thought of as morality taxes. We failed to realize the dangers of using oil, but that doesn't mean we created the taxes to some how make people pay. The excise taxes are generally used for roadways, road repairs, Interstates, and other similar projects. Taxes from gasoline go towards the infrastructure the gas use requires.
While many people are upset with additional excise taxes, they are not a morality issue. The government uses the excise taxes on items they may feel are not in the best interest of people to consume and are hoping to limit that consumption. When people choose to pay the extra money for those items, the government happily makes more money from the purchases.