This whole thing is a bunch of make believe.
It's so Tesla can introduce a business case model which is great for them, but it's not reflective of the consumer at all. As evidence look at the poll result. Why in the world would a person with a $100K share it out?
The plan is about Tesla's network which means they're going to get a cut of the profit. Odds are they'll have lots of cars within the network which brings down any money you make on your car. It will quickly get to the point where you won't make diddly squat on it even if you did go for it.
Now now.... you cant really have it both ways, either no one would share their car, in which case the plan would die off, or so many people would share that you would not make any money, but probably not both.<grin>.
Looking at the above numbers, almost 6% of people said they would definitely share... which if you extrapolate that to say 100,000 cars means that 6,000 cars could be in the system, spread across whatever Geo's they launched this in. (say 20 cities across the US? that would be 300 cars per city.)
OK, Honestly, I don't have any numbers to go further than that to know if it would get to the diddly squat point or not (I don't know the market, or the saturation points, or realistic charging, or... lots of unknowns... ) but it doesn't feel impossible to me.
I also think we are so far away from this being reality that we are mostly talking about science fiction at this point anyway. First we will need to see autonomous cars actually working well enough to be let loose. then we need to see the various governmental regions approve it for personal use (I suspect it will be approved for use with a driver in the car for at least some period of time before it is approved for completely unattended use) then we will have to fight the local political power of the cab companies and drivers unions since operating this (with model 3's at least) would be FAR cheaper than running Cabs or Uber or anything else!
I also suspect that the people who will jump on this first will be the delivery companies. I'm sure that for companies like 7-11. McDonalds, Target, Costco, Walmart, etc, the idea of autonomous delivery trucks from warehouses to stores would make their accountants have wet dreams.
BUT, having said all of that, if no one dreams about this stuff and tries to push it forward, we will never get there, so I applaud everyone who is trying to do get it working, and if you, (*like me) don't plan on letting them use your car, no problem, that's even better for the ones who do!