When people say they believe marijuana should be illegal because they think it's a gateway drug,

I wonder if they were told that bicycles are a gateway to being in a bike gang, they'd try to make riding a bicycle illegal too. Lol cause everyone in a biker gang rode a bicycle when they were a kid so therefore riding bicycles is a "gateway" into being in a biker gang. One day someone will say, "pedal bikes make me nervous, I don't let my kids ride them and they should be illegal because I know someone who rode them when they were younger and now they're in a biker gang!"
That's what I think when I hear someone say they're against marijuana because of something that happened due to a completely different drug.