I thought the same. It seems to me that a "business person" is someone who runs a business. A Good "business person" runs a successful business and a bad one runs an unsuccessful one. A lot can be said about the way 37 signals self promotes but its hard to deny their success.
Personally I learned a long time ago that there's no business book that can tell me how to run my business. You read some good, some bad and if you're lucky find a few good pearls of wisdom along the way.