It may be that, in at least some industries, ruthless aggression is a financially advantageous attitude. Investment banking comes to mind.
If we want to change culture, it has to be for reasons other than money. The Pyramids were a phenomenal project that we couldn't realistically replicate today (due to costs), but I'm okay sacrificing that for not using slave labor. Speaking of which, the American South was an economic powerhouse with a culture of slavery and brutality (in large part because of it, not despite it.)
I think that's what a lot of people are grappling with in Silicon Valley. We want to have a positive, inclusive culture and also build massive companies. People rarely talk about what happens if you can only choose one. The reality of taking venture funding is that you are expected to do the latter, with the former a nice to have.
(You can read my comment history to see that I'm strongly against these types of culture.)