The suggestion was that white people don't get punished when they are guilty, while at best, black people are.
That's a failure of the system at punishing white people. You have a point only if you can show that most blacks are being punished when they're actually innocent. If they're guilty, then they should be punished.
Tesla took a huge risk by taking a completely new technology (battery-powered cars)
Electric cars have been around since the mid-1800s.
There are also some careers where nobody wants a mediocre practitioner. When one's freedom is on the line, nobody wants a mediocre lawyer; when one's life is on the line, nobody wants a mediocre doctor. Therefore, why should it necessarily be the case that companies would want mediocre programmers? Some programming does have life on the line: software in cars, planes, nuclear reactors, or Therac-25 radiation machines; or people's or company's finances: software in banking or stock trading.
There are also some careers where you simply can't succeed at being mediocre, for example any kind of research scientist: if you don't publish good work (and have the kind of innate ability to enable you to do good work so you can publish), you simply won't succeed. How do you we know whether programming is the kind of job where one can be mediocre and succeed?
I've interviewed lots of candidates, many of whom claim N years experience in language X. I'm often stunned at how much many don't know -- stuff that anybody who completes a CSX101 or algorithms or data structures course should know. Is that mediocre?
Why are we carbon based and not silica based? Either works just fine.
No it doesn't. If you do the chemical equations for respiration using carbon, you end up with CO2 as a waste product that's easy for an organism to get rid of since it's a gas. If you substitute silicon for carbon, the equations still work but you end up with SiO2 as a waste product -- sand -- a solid that's pretty much impossible for an organism to get rid of.
Never trust an operating system.