Amara said:
(Personal note: I am biased because I have witnessed the very bad effects on a person's personality due to abuse... so it is not necessarily about ignorance of innocent use as it is a damaged opinion on account of over-exposure.)
You know that general note wasn't directed at you right?
In some cases it might me a damaged opinion but overall it's ignorance. Weed is a drug and the word "drug" scares people. A lot of people don't look past that label.
Even if you have a damaged opinion, don't you know a lot of other people who smoke weed and didn't get any problems? If weed has bad effects it's because the person can't deal with them. Whether because of psychological problems or simple weakness.
And if they can't deal with weed, it's up to them to say stop before it gets out of hand.
I have a disorder that a lot of people have and weed tends to trigger that, makes it worse even at times. But how can you say it's the weed when it wouldn't happen if I didn't have the disorder? Weed is just a trigger, which is very important to remember.
Drugs go wrong when the person using them can't handle them. Another example of this is religion.