That is surely true. Everything you do is a choice, a personal decision. Those choices affect other people, most of the time. That is why responsible choices are important.
The question on the table is not "to smoke or not to smoke." It is whether it is irresponsible or disrespectful to your partners to train with them while you are high. Maybe the answer is to ask them. If you want to be high on the mat, perhaps that's okay as long as all your partners know that. If you're teaching, then your students should know. If they stay around, then cool at least they are making informed decisions.