ADA:
Perhaps you might rewrite your critique of my comment differently if you would study the subject matter. I did so and have amassed a sizable stack of references. Smoking is not just assur as a chumrah. It is halacha psukah. I can provide you with documentation and references. The poskim issuing such psak are the same ones that the general Klal Yisroel – Shomrei Mitzvos – Olam Hatorah revere as their Gedolim. It is correct to note that Many greats of yesteryear smoked, some quite heavily. That predates the extensive documentation on the dangers. Others may have found out more information when it was too late for them to stop. I believe one of the heavy smokers, Rav Fisher ZT”L from the Badatz in Eretz Yisroel continued smoking after he was already dependent on an oxygen tank. He had staunchly refused to concur with the issur on smokinig issued by his colleagues. However, he did make a public statement sometime closer to his passing that he regretted smoking and not being more challenging as a posek. He declared it as an absolute issur.
As for the tons of poskim, I suggest you seek the education about the subject. Here are two seforim you should purchase (or borrow) and review in detail.
פאר תחת אפר
חיים ללא עישון
I will not bother to copy the list of poskim whose statements are quoted there. There are prior threads on the subject in the CR, and you may be able to search and find them. I’m not becoming defensive here. You do not favor smoking any more than I do. But I am relating the strength of the piskei halacha issued from our Gedolei Yisroel, and I am providing resources that prove my point.
Lastly, the aveiroh goreres issue is a decoy. You and I do not know what these bochurim do when away from view. We do not know the sincerity of their connection to the RBSO when confronted with physical desires. No, I would not expect to find a yeshiva bochur who smokes sneaking into Burger King.