Agreed, it usually takes less than a minute to figure that out.
Albeit, I usually don't ban it unless I find them hopelessly close minded when it comes to debates. For other subreddits, I follow them once I have seen them enough times to like them.
Say we had a Twitter or Reddit but without the folks who eat babies. Wouldn't those still be super useful for the majority who don't eat babies? Or would they be worthless because there is some limit on the content?