During the Rise of the Tomb Raider panel at GDC, the developers revealed that they greatly took into consideration how absolutely nuts Lara Croft seems when she’s just straight up murdering people.
The head writer, Rhianna Pratchett, noted that this time around they needed the enemies to be even nastier in order to make sure Lara’s moral compass wasn’t compromised. The idea is that if you’re going to have a relateable hero, you need to make sure the players understand why they’re going around shooting up a storm. Otherwise, there’s a disconnect between whether this character is one that the audience should be rooting for to begin with.
The solution is to make the reason a necessity to Croft. They needed to make clear that if she didn’t light those enemies up in those tombs, they would kill her. The relateability between the character and the player was at the forefront of their minds as they wanted to form this story of ordinary people thrust within extraordinary circumstances.