Sure, I get that, but isn't the Test Track ride system essentially an enhanced omnimover? So, depending on the "meat and potatoes", it could be a completely different experience for the guest. If done well, sometimes even a simple ride system can be themed in a way to create a new and exciting experience for guests, which is what Disney has done with the omnimovers and boat rides. I can't say the same for hub-and-spoke spinners though, because for me these are all the same, unless they decide one day to enclose one, then I might change my mind, depending on how well the theme is executed.
No offense, but to say a ride system shouldn't be re-used, just shows a lack of imagination. Sure, there are limits to some ride systems, and those do limit what can be done, but with proper theming and guest interactivity, you can do a lot with the same ride vehicles. Disney has shown this repeatedly with many of their attractions.