I appreciate you stating your view.
I'll step from behind my veil of anonymous keyboard warrior and tell you a little something about me.
I'm in my mid-40s and in my adult life never got comfortable with the idea of starting a family until ultimately making the decision, for a variety of personal reasons that I won't detail, that I have no intention of ever getting married or having children. I've had many friends tell me I'd be a great dad and I adore some of my friends' kids, but it never felt like the right choice for me.
I have a job, pay my bills & mortgage, call my parents on the regular, am kind & generous to my friends, attempt to be law-abiding, and donate to charities and other causes, chief among them GT Athletics.
At my core, I'll readily admit, I'm ultimately a selfish person, not at the expense of others, but in the way I allocate my own resources towards myself, my interests and those I'm interested in.
Based on what I just wrote, I'd ask you to please reconsider the way in which you apply generalities or, possibly, personal definitions of societal norms to frame up what a "responsible adult" may be. I recognize you used the qualifying word "Generally", but I think you'll find there are more & more people out there who fit the "responsible adult" bill, while choosing a different path than starting a family.
Just a request to consider a differing point of view on lifestyle choices.