This statement does comply to the guidelines of critical thinking. To start, I feel this statement shows a lot of uncertainty. The words used in the first sentence, "pretty obvious," show a lot of uncertainty. If the person was certain, he or she would have used the word "obvious."
Another way this statement complies to the guidelines is the reliability of the evidence provided. The use of "almost all people" in the statistic instead of a concrete number shows that the statistic in the statement isn't all that reliable. This also shows some uncertainty in the statistic.
This statement is a mixture of an opinion and an unreliable statistic. There is no proof that marijuana makes you desire or "crave" more potent drugs. What about others factors such as genetics, familial, or environmental factors influencing drug use? I feel that the reason more people try marijuana before other hard drugs is by chance, because it is more readily available at a young age. Critical thinking is important in everyday life, especially when having discussions with peers over controversial issues, such as racism, gender difference, and homosexuality. It is important in this instance to think critically to come up with alternate explanations for events or problems, without using emotional reasoning or previous bias and beliefs.