Sin taxes as they are referred to can be used as a tool to elicit more healthy behaviours. But many as you point out will divert funds from say groceries or retirement plans in order to cover the subsequent increased prices for the tobacco or alcohol,( another favourite target for taxation).
If the revenue acquired from the taxation of these products is used in a manner that benefits the people such as infrastructure and development of science and technologies that will lift people to a greater standard of living, health and well being then the taxation is justified. However given the inefficient ways government runs and spends tax dollars the extra revenue collected usually ends up in the pockets of donors who fund campaigns to elect the politicians in power, croney capitalism if you will.
Author
J.R.K