Businesses actually require even more relationships than standard wage slaves. Consultants need to be even more of a "people person." The main difference is that, for an owner, they "have no boss." (In quotes, because customers tend to be even more demanding "bosses," than managers).

My experience, from knowing quite a few business owners, is that they are always "angling for the edge." They want to squeeze every bit of advantage, out of every relationship/deal they have. Almost every relationship is adversarial and competitive. Lawyers can be the same way. The best ones, consider every interaction to be combat.

I'm not wired that way, so I'm not a particularly effective business owner.