That says 'myth number 2', and then it says 'Marijuana is not addictive'. It states that some people can get dependent on it, which is an addiction. Also, in the thesis, it says 'It was once believed that Marijuana is not addictive; many people still believe this to be the case'
The word 'still' suggests that people who do believe that Marijuana is not addictive are wrong.
Altho I don't know whether it is or not, that site and your opinion say different things but you use the site as a reference! It confuses me!