Many users dislike the vB Admin CP, and many would choice IPB's over it anyday.
Also may I ask if you used the demo before buying the software? It seems that all you do is complain about the product when you didn't do your research before hand. The product is highly customized, you can skin the front end and backend any way you want. It is good feedback you provide but don't be so stuck up about it, be constructive.
I bet the new generation cares more about eye candy than usability. It is the old folks that care more about usability. Give it time...
IPS offered to make it compatible with the next version right? Why would they continue to support it when IP.Content can do the exact same thing but better.
Do you want IPB to be the best it can be? Why should they waste time updating the portal when they can focus their resources on more important things?
I don't know about you but there is documentation even a video on how to install IP.C... Oh and your license comes with ticket support and access to the support forums. Where I am sure someone would be able to assist you. I do believe IPS also offers free installation, look at that the battle is already half over.
With a little effort on your part you can get it working.
Isn't it just editing the application and entering the name changes the tab name? Doesn't seem so difficult. Everything has a learning curve if you are to full of yourself to attempt to learn or ask for help them it's a shame :(. Even Wordpress has a learning curve to it.