You're missing the point. It isn't that others don't smoke pot, or whether it is a bad drug or not, it is that they knew a test was coming and that failing would cost them millions. It is about them and their decision making. They may only be college kids, but they are college kids who are not thinking clearly. Teams cannot tolerate much trouble at all these days, and they HAVE to be thinking, "If this kid cannot keep clean for the most important drug test of his life, what is going to happen after I put millions in his bank account?"
It is like dating. It is like going to a meetup dinner party hoping to find a long-term girl friend with a motel reservation sticking out of your shirt pocket and a bunch of condoms in your hand. Yes, people who date do go to motels and yes, condoms are a good idea, but advertising such before you begin a relationship is no way to get selected. (Women, substitute carrying a copy of Bride's Magazine and a wedding planner. You get the idea.)
If they thought they could beat the NFL system with a supplement, it is even worse. They are telling teams who are considering drafting them that they think they can beat the system. Just what teams want to hear these days.
Sorry, these kids made a bad mistake. They deserve a second chance, and they will get one. They will go on the second day instead of round one. The point is the millions of dollars difference they cost themselves by not being able to stay drug-free for a couple months before a test they knew was coming.