That's a great analogy, but I'm a bit confused about the later part, is it "you'll never be wanted for work as ..." or "you'll never want to work as ..."?
Anyway I looked it up, seems it's a legit usage, my bad.
Akin to "for want of a horse"
Another way to think of it is simply another slightly different meaning for the word "want". Just like in "for want of a horse", or "was found wanting", you can replace the word "want" with the word "lack" in all these examples.
"You'll never lack for work", "the project stalled for lack of engineers", "the code was found lacking"
"Want" may be used as a drop-in for "lack" in each of those.
You could also just say "lack work" instead of "lack for work". But that doesn't really make the "for" redundant. Though I can't explain the reason why not.
Maybe the "for" in "lack for X" or "want for X" is like the "for" in "look for X" or "wish for X"
> You could also just say "lack work" instead of "lack for work". But that doesn't really make the "for" redundant. Though I can't explain the reason why not.
I think it's just that "want" in its original usage is a noun. "Wanting" in "found wanting" is really a gerund of "have a want," not a gerunding of "want." "Wanting" as a gerunding of the verb "want" doesn't necessarily imply a lack. "Wanting to go to the park on Wednesday" doesn't mean you lack anything.
1. a lack or deficiency of something.
"Victorian houses which are in want of repair"