Welcome to the Babble!
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You ask some interesting questions. I will take a swing at a basic answer. First, who says any of these hosts are rated as you say? The truth is, there are many lists and almost all of them are really sites trying to sell you the host that pays them the most. There are some good recommendations to be had, but you need to read with a jaundiced eye.
As far as SBI, Site Build It, it is in a different category from standard hosts in that it is a complete program that helps you build a site, but more important helps you choose a profitable niche, learn to write material that appeals to web viewers, and much more. They have many tools to guide people from start to finish, what some would describe as "hand holding." They do have a proven record of helping people succeed online, but after learning the ropes most people like to operate more independently. Some people find them somewhat limiting, others find them a great help. You can read about a lot of different experiences if you just use the site search here and read a bit. Also check out Lisa's comments on her 2createawebsite.com.
Glad to have you join the forum, a great place to learn and share.