It is a really clear and easy pattern, really a collection of behaviours on the part of website hosting corporations. To sum it all up in a single word : ethics. The most significant goal is up-time – most anything can be forgiven so long as sites are running, as near to one hundred percent of the time as practicable. Each time I have had to switch web hosts, this was the base reason. But the basic reason explaining why I create and maintain a website is so folk can see it – and they can't see it if the site is down. By registering the domain at a different company, you will very likely get a lower price, and you may gain autonomy from your internet host.