The problem with one clicks in general is that dreamhost is horrible about keeping any of them up to date. Recently wordpress has been an exception to that statement.
I don't remember off the top of my head if it was Joomla or Drupal, but one of those had a one click install, and the "next version" installed differently or had too many choices in the upgrade process to "upgrade automatically". There was a stream of people posting in the forum requesting they upgrade, but it never happaned and ultimately the one click install simply disappeared.
Dreamhost is driven to offer one click installs by competitors in the industry. Truth is shared hosts all like to advertise that item. Fact is a one click install is not required, and really only saves a few manual steps that if you're proficient are very easy to do yourself.