"Jambo" is a problem, like "tatizo", "tata" or "shida". For that reason, the common greeting is a discussion of the lack of problems, and all the prefixes are negative. "mimi sijambo" literally means "I am without problems". The answers given are culturally accurate, but lazy, and if you teach conjugation this way you will confuse your students, who are looking at this as a positive conjugation, "ni/u/a", when it is actually a negative conjugation "si/hu/ha".
So from what I gather, verbs are conjugated differently when they are negative from when they are positive? Like if "sijambo" means "I have NO problems" then "nijambo" would mean "I have problems"
Firstly, it's not that hard, other languages (German for example, my native language) have much more difficult grammar. And secondly, if you don't like the language, you don't have to learn it!