This is a legitimate question. This robotic snake problem is solving a problem that does not exist.
And, please, don't invoke the handicapped card as someone already did. They manage just fine today. Anyone, handicapped or not, who qualifies to drive a car can handle plugging a cord into a socket. A 7 year old kid can do it.
So why throw a $30,000+ robot at a non-existing problem. I'll tell you why:
Musk understands marketing. With oil prices so low and nothing significant coming out of Tesla they all but evaporated from public view. There is/was no news to be had about Tesla. The SUV is tanking. That's a non-story. So, how do we get people talking about Tesla again. We put out outrageous-yet-brilliant-sounding futuristic ideas that are easy to consume by the average Joe and blog writers can parrot liberally. Musk/Tesla sound like geniuses and the general public doesn't even take a millisecond to apply critical thinking to what they just read.
The ONLY way a complex robotic auto-charge system might have a tenuous level of applicability is in the context of self driving cars AND "driven" by people so extremely handicapped that they would not be allowed to drive a car today. In other words, paraplegic, severe Parkinsons or other ailments.
That scenario is decades away. And, even then, a simple drive-on docking station would be far cheaper, reliable and easier to install than some kind of a robotic snake rig.
I love technology as much as anyone on HN and i have been involved in industrial and educational robotics my entire adult life. Yet, I have to be honest with myself and not treat everything like a nail just because I have a hammer.
So Tesla will sell you a $30,000 robotic snake for your $80,000 car while Toyota will probably sell you a $3,000 floor-mounted docking station for their $30,000 car. And so will all other manufacturers. Because it makes sense.