Very low chance? Every woman i have ever met has had a sexually negative interaction with a man. Yes individually the risk is low, but when looked at through the lense of power dynamics it just makes sense. Do you have issues with women only gyms? Safe spaces for women to work out without being oogled? Or women only sports clubs where they won’t have someone try and “show them proper technique”? I used to think like you too, I would never do these things, so why are women complaining about this, its not fair to me. But then I matured, and I realized how that even if I wouldn’t there are far far far too many men who would, and who have, and from that perspective, women only ride share is good. No one is saying that all women have to use this option, its available for those who dont feel comfortable, maybe they were recently sexually assaulted, and they dont want to be alone in a car with a man, you cant blame them for that, even if the guy was the nicest person in the world. If you cant see why that woman would be uncomfortable or even afraid in that situation, I dont know what to say, except that I hope you take a step back and look at the wider world.