i believe no one is dumb enough to purposely go 190kmh where its allowed to go 80kmh in a turn, even more so because he called the control center and informed that they're going way too fast and its too late to brake (trains literally take kilometres to brake).
so there has to be something more to it than just a dick driver (not saying that he's not one though).
anyway, it's easy to just put all the blame on him, but i saw quite a few articles about this, and most didn't match and it seems that people are just guessing.
also, this line is supposed to be driven in 190kmh, its just this small section where they have to slow down, and he didn't for whatever reason.