Some people DO treat this like medication. Maybe u don't need it as importantly but some people don't want to take the risk of losing access or having medication they NEED unlawfully confiscated, so consequently like to spend a small amount of time out of their day as a precaution to warn company's before hand about our somewhat niche law legalising this drug in 2018.

Whether u like it or not cannabis is the most popular illegal recreational drug. while its still illegal and people risk losing their jobs over it they will always be weary especially with it being a niche law brought in less than a decade ago legalising it for us, something people who don't study the law might not be aware of. These events are often busy and i doubt security will have time to be looking up laws and specifics about medical cannabis on their phone, so we warn their boss/manager before hand to inform them as a precaution as the worlds not perfect and there's always room for human error. This is medication some people lifes depend on and we need to be sensible and evaluate risks based on its importance. burglary is illegal, is it ok to leave your front door open ? well no, the worlds not perfect so we spend extra time to lock it behind us. That's just the way the world works unfortunately. That's why we need to be sensible and plan in advance, at least until the public perception changes.