Like Metroid Prime happens entirely because she saw Ridley on the frigate and wanted to kill his ass again because she hates the shit out of him. She wasn't an empty shell.
I mean that's what took Other M's characterization from bad to insulting. We had a sense of who she was before then: cool lady with bird alien DNA that lets her wear cool armor and fight alien monsters, hates space dragons.
Samus crying at the site of Ridley would have been dumb and bad either way but everyone hates it because it is literally the opposite reaction to what is expected based previous encounters being met less with tears and more "I'm gonna kill it!"
It was pretty obvious to me that they were going for a reimagining of the character without rebooting the series
"Why didn't Samus react this way in all the other games were this new direction didn't exist yet" was always a silly point to make
You could already see where Other M went in the Zero Mission comics so it wasn't as much of a leap on part of the writers as people who only play the games might think
It cannot be stressed enough how incredibly flawed every part of Other M was from conception. Completely failed to understand what people liked about the games, what the character meant to the people who would most likely be buying it, and had no concept of how games had progressed as a medium since like 1994 or whatever.
The character didn't mean anything to most people beyond "badass woman who shoots things", that's why any deviation from people's headcanon built up over the first 3 games was met with negativity
If you want to flesh out Samus, "badass woman who shoots things" isn't going to cut it