Tomb Raider was always multiplat for many, many games, and has also been heavily associated with the PS brand for right or wrong. It's also a bigger franchise than Bayonetta. I can fully understand some outrage from Sony gamers who may have loved the games since PS1. It's not unlike Nintendo fans being happy with FF7 going to PS.
I don't think this will kill the franchise, however. I lost interest when Lara got a boob reduction.