Marijuana legalization is a hot button topic, though most polls are highly in favor of allowing medical marijuana along with a slight majority showing a preference towards legalizing recreational marijuana. There are 24 states that allow some form or another of medical cannabis but that hasn't made the NFL change their stance on the issue.
One player specifically has started a larger conversation about that issue, Eugene Monroe of the Baltimore Ravens. It might not sound like a big deal to the everyday person for an individual to advocate for medical marijuana, but when that person is a highly paid athlete in a sport that still restricts it's use then it is actually a big thing to be vocal about.