For a long time (when emissions killed C3 performance) the Corvette became a bloated GT rather than a pure sportscar, and people still built them up, customized, and tuned them. Heck, people tune minivans, old boxy volvos (just plain safe family cars), and one person took a last-generation Saab 9-5, converted it to RWD and managed to shove a Viper GTS engine under the hood. Don't forget that the AMG Hammer that
It's not for you; I get that. But some of us want to tune the drivetrain and suspension for performance -- to heck with the soft ride. We like the lines and the interior and the potential the platform provides. The
G70 sibling shows what the platform is capable of with minor tweaks, but by comparison the interior and exterior are less exciting than the Stinger, and the back
seat in the
G70 is useless for adults.
And... other people may want to mod the car for a softer ride and hang fuzzy dice from the mirror and maybe bedazzle the dashboard, or rice it out with double-decker wings, lower the car and dial in a crapton of negative camber for the "stanced" look and slap on a few greddy turbo and thrush muffler decals.
If everyone had your mindset, Mercedes would never have made the AMG hammer, because the car it was built on was a luxury GT, and we wouldn't have today's AMG lineup.
It's also worth pointing out the CTS-V is built on a luxury GT platform. I've ridden in and driven a built+tuned CTS-V and it was phenomenal.
Different strokes for different folks.