I don't really like talking about it anymore, I am 6 years sober and still dealing with related issues every day, but yes I feel like I can't talk openly about it. Skepticism is exactly how I would describe it. It's not strictly stigma, like is the case for most people who talk about drug addiction. It's most often a reaction of surprise, disbelief, and then resentment, like I'm a sleeper agent for reefer madness propaganda that they've just uncovered. Normally when you admit to a previous drug addiction that's had lasting impacts on you, the "bad result" is "Wow, I can't believe you're a druggie". With cannabis it's more like "Wow, I don't believe that that happened actually, weed is safe girl, it cures cancer". It is what it is.
I think it's common for people to forget that the substance is not always the addictive part by itself. It's just as easy to become addicted to the side effects, like how it makes you feel or not feel. It seems to compound the judgement problem quite badly.