I suspect this sentence has a context we are missing. Like, the Jews were without direction until Moses came to lead them. I suspect this use of rumbo has more do to with a lack of emotional or spiritual direction, rather than physical. Just like the equivalent English sentence, "the people are without direction".
The word can be used both ways: physical bearing or emotional direction. Just like the isolated Eglish sentence: I have no direction. could mean "Without my GPS I don't know which way to turn." or "I have dropped out of school and don't know where my life is headed. " But I love your Biblical reference which incorporates both--the Jews were wandering and they had little emotional direction, too. Saludos.
It is excellent that you remember these specific examples. Unfortunately, these are all colloquial and just need to be memorized because that is the way native English (at least, native American English) speakers phrase it. I suspect that just as native Spanish speakers are tolerant when Spanish students forget to use a tonic a, native English speakers put things in context when the article used is one that they themselves would not use.
General nouns do not require definite article in English. "la genta está sin rumbo", "las personas están sin rumbo" - PEOPLE are without a course, or without direction. Just like: "Me encanta el fútbol"; unless I am speaking specifically about THE football that I have in my hand or something, it means "I like football/soccer." ¡Ay, por favor!
"Those people are without directions."
Depending on context, "directions" can be correct. "I need directions to get to X" "I was given bad directions, and now I am lost.
"Direction" and "directions" have different meanings in different contexts.
"I was given bad direction when growing up, and now I am a delinquent."
"He needs some direction in life"
But probably NOT, "I need direction to go to X" or "I was given bad direction and am now lost."
(I reported this)
No direction home, like a rolling stone. My dictionary gives only meanings related to moving in a particular direction, but any language can use words figuratively. People will do this whatever the dictionary says. Logically, this is a lesson about directions, North, South, left, right. Best leave it at that if you want to keep the green owl from biting you.