Introduction
Rambam was the most famous Rabbi of his day. He interacted with Rabbis, scholars, the royal court, and simple people all over the world so it's important to understand the audience and context for each work he produced.
Rambam saw how fractured and confused the whole entire Jewish World was in his day so he sought to provide a Standardized Halacha and Hashkafa for all of the people. With that understanding in mind, you can darn well believe that Rambam thought long and hard about every word he wrote.
In his old age he was the leader of the Jews of Cairo, Head Physician of the Islamic Empire, and Foremost Poseik of World Jewry. These duties gave him almost no time at all to produce new works. He made only two exceptions. These were on the 4 topics which he felt were most necessary to understand and yet almost entirely misunderstood.
• Letter to The Chachim of France: "On the Definition of Avodah Zara
• Letter to All Jews: Olam Haba, Moshiach and Resurrection of The Dead
Rambam believed that the Jews of his day might lack the sophistication to understand the true definition of Avodah Zara but that every Jew in his own day and for all time thereafter needed to correctly understand the meaning and purpose of Olam Haba, Moshiach, and Resurection.