No, see. The concept of "rape culture" doesn't trivialize rape. But I think it's reasonable to refer to cultural norms and behaviors which do in fact seem to promote the idea that rape is an expected or normal thing as "rape culture".
I admit, I was pretty skeptical of this notion for a long time, because it seemed unreasonably extreme. Then I saw news coverage about some people being tried for rape talking about how it was going to be bad for their careers if they got convicted. Then I saw high school athletic coaches saying they were going to educate their boys on, get this, the importance of not filming or talking about it if they sexually assaulted girls.
Now I concede that, yes, there really is a larger-scale problem that is going to have to be addressed. Yes, personal responsibility is a thing, but the fact is, statistics are also a thing, and if doing one thing at a societal level increases the number of rapes, and doing something else lowers the number, doing the former thing and then complaining that it should be all about personal responsibility seems pretty, well, irresponsible.
And while, yes, we can totally continue to meaningfully blame people for their own choices, I think it's pretty reasonable to think that adults going out of their way to tell boys how important it is to avoid getting caught, rather than how important it is not to sexually assault people in the first place, could create in boys the impression that such choices were accepted and respected.
A non-zero number of rapists do not realize that what they did is actually rape. Because they've been told that it's okay for girls to cry, or that girls owe them sex and it's legitimate to push the issue, or whatever else. And yes, people really get told that.