Good for you... but truth is you're probably an exception.
Not everyone can code; it requires a very specific mindset and very specific way of thinking to effectively code. It also requires a desire to code. Being a carpenter probably actually set you up much better to be a programmer than you think; it's all geometry and understanding load. I know because my best friend happens to be a carpenter. A coal miner... well I'll be honest I don't know what skill set is required for that but I'd wager that it falls into the realm of unskilled labor, whereas carpenter is definitely skilled labor. There's a difference.
Now on my second point; desire to code. I'm really good at coding. I learned at an early age, self-taught and was writing assembly language stuff in my teens while my class at school was struggling with Pascal. I wrote tight, well-written code that I shared with friends and took code they shared with me and together we built great stuff including a game... which granted didn't do well but it was a hell of an accomplishment for four teenage boys with no Internet and communicating mostly through the phone and by mailing floppy disks. But when I was in my 20's I realized suddenly that I didn't like coding. I still don't. While the feeling of accomplishment was great when something worked, there was a degree of slog in getting there. After a fashion I made the realization that hardware was where I found the most interest, not software. So I pursued work as a hardware engineer in embedded systems.
Now at 40 I have settled into being a (well, actually THE) storage administrator and systems engineer for a multinational company... because it interests me. The skillset is extremely specialized, but used in a lot of companies and so therefore isn't going to leave me without a job anytime soon. The risks are high because if I screw up I potentially affect a lot of people, but the rewards are also pretty damned good. The closest I've gotten to coding in the last 20 years has been writing scripts to make my job easier. I do it quite a bit, and while it's similar to coding it's far more focused on immediate needs. I still build great "code" but it's an adjunct to my day job, not my entire day job. I think if I were to code for a living I would've quit long ago to pursue something more enlightening. But that's just me.
Also be aware that there are people who have no desire to learn. I've dealt with them many times too. They settle into unskilled labor not because their brains can't handle the information but because they choose not to. And add to that whether you like it or not as one gets older it becomes far harder to learn a new skill. Add all these factors up and yes... Bloomberg is probably right on this one. He's an ass, and quite often wrong... but on this one I have to give him credit.