Earlier quoted context omitted.
Now imagine the exploit being used by a blackhat. The hackers aren't the problem here. The fact that somebody can even control cars over the Internet at all is.
You seem to be confused. Because a dangerous threat exists does not give a researcher license to endanger the public to prove it. This is especially the case when a safer alternative to demonstrate this exploit easily exists. Robbers could enter your home and hold your family at gunpoint AT ANY TIME. That does not give me the right to prove to you how easy it is by entering your home and scaring the crap out of your…
If you read the article, you'd know that said safer alternative was already attempted and presented to auto manufacturers, only to be met with dismissal.