Suing gun manufacturers
That's not the same thing AT ALL, because today's gun isn't some futuristic sci-fi thing where you identify a target and after you fire it steers the bullet around a corner into it (or into a bystander if there's a bug in the gun's software) If the gun maker should be liable, then Ford should have been liable the first time a Model A ran down a pedestrian.
I agree the user has to bears a lot of the responsibility, but for something like this I'd argue (as would a lawyer and undoubtedly plenty of 'peers' who would sit on a jury in the US) Tesla 'should have known' would cause problems. The misuse doesn't even have to be deliberate - people sometimes fall asleep while driving today. How much easier will it be to nod off when you don't even need to keep your hands on the wheel?
That's my #1 dream about getting a self driving car - instead of getting up at 5am to catch an early flight and make a connection at a hub where I catch a second flight, reaching the destination that afternoon, I could simply have my car leave at bedtime. I'd fully recline and sleep, then surf the internet or watch movies after I wake up for the rest of the trip, and reach my destination earlier, more rested and more stress free!
This isn't a "creative idiot finding a way to misuse their products", but someone using it as intended but not following every recommendation. While the driver would undoubtedly be found to be at fault as he knew or should have known the car couldn't handle all situations and his attention may be required at any time, that won't stop Tesla from getting sued. Because they would bear part of the blame, and more importantly for the lawyers and their plaintiffs, they have much deeper pockets.