I would kindly invite everyone to calm down with this anti-religious fervor. :) This is just a greeting, and it means "peace be upon you". I understant that the anti-religious propaganda in the Western world has made people extremely knee-jerkish, but please, this is just language learning. If you have a problem with "assalamualaikum", you should also have a problem with the word "goodbye", as it comes from "God be with you". Shall we banish "goodbye" from English Duolingo? :D Peace be upon you, and God be with you.
Connotations and implict meanings matter; don't be a troll. "Goodbye" does not actively, in the minds of modern speakers, contain religious implications, where as this phrase very much does, and signals belonging to a religious tradition.
You're etymological argument isn't the clever "gotcha!" you think it is
This is NOT about religion....its about the fact that this work is almost never used in day to day conversations when one or people are not Moslem. I lived in Jakarta for over 3 years and never heard this used outside of formal meetings or amongst my Indonesian family when they didn't realise I was there.
This should not be included in this beginners course.
As a Bule who's been spending about 2 months a year in Jakarta for business over 4 years, I've never heard the word used towards me, if at all. It's used mainly muslim to muslim as far as I can tell so It pretty much has no value for me....and it's really difficult to spell!