It's not a good reason, it's just that alcohol has been in many cultures for thousands and thousands of years. In terms of harm to the individual and to society, alcohol rates as a class A.
Its stupid the amount of people that die from smoking and drinking compared to the big fat zilch that die of smoking cannabis yet they bump it up to a class b?
Cannabis **** with your head big style
Thats all
If thats OK for you, then smoke away. Reality is a foreign country
Depends who you are and how much you smoke, but it certainly has that capacity. Similarly, drinking too much too often will **** with your body, and that's more indiscriminate.
All things in moderation.