You missed the 'or further limit his CPU share' part. The entire point was that they had options to limit his affect on other users without directly accessing his instance.

In this case, they also have given the users the option of the 'master key.' Their ssh key is in the authorized_keys file by default, but the users are allowed to removed it. To me that is a statement to Rimuhosting that this customer would prefer that they did not access his VPS directly.