I recall a T-Shirt: "Everyone is born left-handed. You turn right-handed when you commit your first sin." :-)
"Most of people" without "the" should be correct. The authors of the course completely מתעלמים that the usage of articles is שונה in Hebrew and English.
"Most of people" is not good English. You could say "Most people" or "Most of the people" and both of those should be accepted.
I think "the people" is good in the sense "the nation" ("the people of the U.S."). You are right, "most people" sounds better. I am not a native English speaker, and may make mistakes. But even I see how many unnecessary "the" articles are demanded in the exercises in this course.