Because the TL;DR version posted on MR didn't see fit to print it.

If, heaven forbid, a person actually took the time to read the source material it would be readily apparent this isn't about Apple at all. It's about Hands-Free in general.
Sometimes it's not about the news you get, but where you get it.
To answer your question directly: Excerpted from the source material
To assess real-world impact, Dr. Joel Cooper with Precision Driving Research evaluated the two most common voice-based interactions in which drivers engage changing radio stations and voice dialing with the actual voice-activated systems found in six different automakers vehicles. On the five point scale, Toyotas Entune® system garnered the lowest cognitive distraction ranking (at 1.7), which is similar to listening to an audio book. In comparison, the Chevrolet MyLink® resulted in a high level of cognitive distraction (rating of 3.7). Other systems tested included the Hyundai Blue Link (rating 2.2), the Chrysler Uconnect (rating 2.7), Ford SYNC with MyFord Touch® (rating 3.0) and the Mercedes COMAND® (rating 3.1).[/I]
I'm not picking on you, but it's a common refrain on MR to deflect by saying "but what about company x" instead of addressing the topic of the post. All of the silliness posted by other individuals could have been avoided by simply perusing the source material. I think MR sometimes edits info for clicks instead of facts.