Ĉar li estas Zoidberg.
"How come that doctor does not have a job?" means the same thing but is incorrect.
"how come" does mean the same thing as "why" colloquially, but I don't think it translates the same way. Though I may be wrong.
I'd be interested to learn about the history of the phrase "how come". My guess would be that it originated as "How does it come to be that [(this) is the case]" and shortened over time until it eventually became just "how come"
so whats the difference between "posteno" and "laboro" ? are there certain instances where you would use one but not the other?
Posteno is a position or post.
Laboro is the act of working or steady work.
Why does that doctor not have a job?
Kial tiu kuracisto ne havas laboron?
Ĉar la usonanoj bombardis la malsanulejon "Kuracistoj sen landlimoj" (MSF) en Kunduzo.
Why?Because of David Cameron
If it doesn't have a job, is it really a doctor?
How can mirrors be real if our eyes aren't real?
Cxar la senlaboreco estas tre alta.