Samus was a completely one-dimensional character up until the releases of Fusion and Zero Mission. Those were the first games to give any sort of voice to Samus. But even this only brings her to two-dimensional. We still have nearly zero backstory, with what little has been written either considered non-canonical, or has only been released in Japan and either still untranslated, or extremely rare to find. But since we have never before gotten any kind of truly backstory or characterization in the games until Other M, there wasn't enough to truly call Samus a character. More of an automaton that we had control over, that never felt fear or any other emotion, just ventured alone into certain danger and always came out unscathed.
Based on what I saw, Other M gives us what was sorely needed for Samus to actually develop as a character. The exposition and inner monologue actually lets us into the mind of who we are playing as, and finally lets us see what kind of person she's supposed to be. It honestly kind of burns me up that people actually disliked this. They wanted Samus to just continue to be the silent badass that can walk into any hopeless situation and come out victorious. That's not a character. That's an unfeeling robot.
What's worse is the streamer's reactions to it all. He was clearly horrified each and every time that Samus talked, and her interactions with others. It honestly ruined my experience watching him play it. I don't think I'll continue to do so, and will instead watch the playthrough I have bookmarked that has no commentary. Give me a chance to pay attention without the constant complaints and horrified responses...