Some of your criticism seems justified, some not. Installing scripts and stuff really is not the responsibility of the host unless you are using a script installer (such as Softaculous) they provide. Installing Wordpress is very easy, anyway. Wordpress boasts a 5-minute installation time but it comes in under that. If you have any problems with that, just ask here at Sitepoint.
As for the support not being preventative or not foreseeing possible issues that may arise, you are probably correct about that. They are trying to resolve tickets as quickly as possible. I sometimes feel sorry for support staff at hosting companies. They get support requests for all kinds of things that have nothing to do with the actual providing of the hosting service or server configurations specific to them. If they do not have a script installer to install Wordpress, you are pretty much on your own in that area and that may be why they were requesting additional fees to perform the service. There are hundreds of open source scripts available. No host can be an expert in all of them.