In my opinion, The Martian had better writing. You could tell Weir was having a blast writing it, and his enthusiasm translated directly to the main character's love of science and enduring sense of humor in the face of almost constantly dying.

Hail Mary felt like it was trying to capture the same magic but missed the mark. The plot felt constructed rather than spontaneous and I couldn't relate much to the main character at all. I agree about the Hollywood motive. I'll probably watch the movie.