People use cannabis for different reasons.There are those that use it for spiritual enlightenment and those that use it for medication as well as those who use it for recreation.And then there is those who use it for all the reasons posted above combined.
I supposes some people use it just because they can or because it is illegal and they rebel at the thought of a law that would tell them they can't.
There is proly a ton of more reasons suited to the individual and I could hardly list them all.
What is important here, I think is...why do you use it?
Answer that for yourself and you can make the decision on whether or not it is important for you.