Simple caring about your fellow humans seems to be off the table let me give you two reasons based purely in your own self-interest to see she gets home safe:
As mentioned, if Something Bad happens to her YOU will be among the first suspects. This will, at a minimum, result in severe inconvenience to you personally.
Women talk to each other. Getting a reputation as a guy who cares and follows social norms (such as seeing a date home safe even if neither of you plan to interact in the future) will benefit your reputation and make it more likely women will trust you enough to date you. Failing to do that will gain you a reputation of being an unfeeling asshole and reduce your chances of dating women who hear of you through the grapevine.
I don’t have a dog in this fight, but when you said “random violence” it implied you were talking about the likelihood of falling victim to random violence. Why would you specify the violence is random if you mean the victim is less able to cope with any type of violence?
I suppose there is a worthy subject of discussion in the question whether men should be concerned in general about their date getting home safely. To think it is a worthy gesture (or necessary gesture) only if you anticipate a second date, however, is a much more troubling position. To me it implies the following attitude: “I acknowledge some danger to you after we part ways, but I will make sure you get home safely because 1) I want you to be alive for a second date, or 2) I want you to think I’m a nice guy to increase the chance of a second date. If you’ve already decided there will be no second date, you’re on your own.”
I think it is okay to assume in most circumstances that adult women are capable of navigating the safety of getting home after a date. The likelihood of a second date should not, however, factor into the equation. I think that’s where the OP is getting pushback.
If you are so convinced that politeness is unnecessary (which, by the way, tells me something about your age and background), then exactly what’s your question and why do you care what anyone’s answer happens to be?
You already have the answers and your dating life is such a wild success as a result that there’s nothing the wise folks here can tell you. If you’re not just poking the anthill here, what is your point?