No one is forcing anyone to buy from Rackspace. The question is whether Rackspace has a unique value proposition against Google or Amazon, and the answer is support.
As long as you are using the private IP or public DNS name outbound traffic between EC2 instances in different AZ's in the same region is $.01/GB, inbound is free.
Pricing is different for traffic going outside the EC2 network.
Elastic Beanstalk, OpsWorks, Google sites, Google apps, AWS Marketplace, etc..
Going by what you said about most companies, most registered businesses in the world are likely just looking for a single dinky site with a mailbox pointing @theirbusiness.com, definitely no need for more than a shared server. Google, Wordpress, Github pages, Shopify, and dozens of others make this very simple to setup and use. You said Rackspace is the only large hosting provider that provides this across the board, that is not true and they aren't even in my top 10 if I was looking for a provider.
For a single website that gets less than 10 visits / day with 5 html pages I was just quoted $75/mo minimum by Rackspace with some server management on my part.
