Yet the firmware is locked down and they aggressively pursue and punish people who try to control their own cars... they may be the hacker car company, but overall they are very anti-hacker.

You're absolutely right. I think Elon is very acquainted with the hacker ethic, he's written a lot of code in his life. People see the celebrity businessman that he is now and they assume he hasn't written code.

He's a hacker that worships money more than open source software. There is a spectrum of how hackers balance riches and fame and being true to their roots of open source. I'd say Linus has done a very good job. Perhaps the best job you can do. Elon is probably at the other end of the spectrum, but not quite as far as the Google lads are. They're at the other end of the pool.

Can this be a safety issue? I’d rather not have a 4k pound hunk of metal flying at me by someone that just wanted to try something out in a cars firmware.

What's the difference between that and say, changing your brake rotors and brake pads? There's a level of danger there if it's not a professional doing it.

In either case the person doing the modification would be found at fault by police / insurance, but with software it isn't so clear cut - how do you know whether or not the car is hacked? Often, the collision will become a national news story, prompting Tesla to perform a multi-week investigation to see if anything in the car was modified, all while they've already lost because news media had already blamed Tesla.