A lot of people can pull off dreads, but just as many people can't. A lot of hair dreads naturally anyway, people with hair like that tend to suit it. There are some people who it just looks bad on, like the dude in that picture.
Try out dreads, nobody minds. But we won't lie to you if you look ridiculous. If it looks bad and you insist on keeping them anyway, you just don't get to complain about any of the jokes you've set yourself up for.