And what about Leo DiCaprio in titanic? Or the trope of the "childhood friend"? How about the success of sexy dads tropes? I guess you are going to cherry pick to not address the elephant in the room: having a job and being able to pay bills but getting home to just let your partner do everything else is not exactly being a good partner.
We associate love with someone who actually care, not someone who says, "I went to work and paid the bills, I'm too tired and you are selfish to expect that I do something at home, you should serve me because I, the man, I'm meant to lead". There is nothing caring or loving about that. On the other hand, the rare man who is actually happy of your promotion even if that means that he won't have dinner ready when he reach home, is something we love. The one who is able to see that you are tired and does the cleaning so you don't have to. Sure, other days you'll be the one caring for him, but it is reciprocal. And he is able to identify what makes you smile for real, not just buy flowers and expects that you perform happyness even if you were waiting for a book and repetead several times that you wanted that book only for him to "forget" and buy the flowers at the las minute and call you ungrateful for not liking them knowing full well that he hasn't care enough about what you really wanted.
Being reliable means that you know what to expect. But many times, what you expect is disappointment. And when you reach that point, suddently you are willing to risk the "not know" what will happen. But it is not about a "roller coaster of emotions" is about ending something that doesn't work for you. Of course, you would only understand this if you start seeing women as people. Each of them different, with their own needs, wants and dreams. Same as men.