No one said they "don't work as good" on a turbo engine. What was said was they weren't as effective -- in other words not as big an effect on the turbo motor as the effect on the NA motor (at least I think that's what was meant).

Ford used twin-throttles on the EFI trucks, but only single-throttle on the EFI mustang hi-power models. Did Ford "forget" to use the twin-throttles on the Mustang? No, they used tuned runners after the plenum.

The point is it's easier and less expensive to use a simpler throttle and then use that money somewhere else, like maybe a better more expensive turbo or intercooler. I'm sure that some of those millions were spent in figuring out where to use the cheaper part -- even when it's not quite as good -- and when it was necessary to use the more expensive part. I'm sure Nissan didn't just tell the GTR development team to "use the best part whatever the cost"!