I think Shinichi actually likes the lot.
Seeing that Shinichi really has very few friends, these kids are considered Shinichi's very first friends, even though they are kids. They don't really despise Shinichi because of his arrogance, but rather, they like him and share similar interests as him. So despite being really immature, Shinichi actually understands that and accepts them as who they are.
However, I would like to note that the DB are actually pretty mature for their age (they are only 6). You don't really see kids in real life as knowledgeable as them or behaving like them. The 6 year old kids that I met love to whine and cry and they don't have much knowledge of practically everything.