In the case of my grandfather, he was very much the traditional family patriarch. He'd stay out of conflicts for a little while, but if he decided it went on for too long, he'd intervene and figuratively knock some heads together and make them get along. No one else either would or could step into those shoes after he died. In most cases I'm no fan of those kinds of traditional structures, but in that side of the family's case, it was what was needed. My mother's mother was also a peacemaker like yours, but she was verbally and emotionally abused by her husband and struggled with alcohol addiction. She had a rough life and rough marriage, but she was so sweet to me while I was growing up. By the time I was 13 she was pretty much gone to Alzheimer's, when I really needed the influence she brought to my life.

Real estate and finance, ugh. No wonder you face such nastiness from them. When you receive such comments, always evaluate the source before believing it, just as you would when reading a research paper.

In your case gender is probably playing a role, since many hetero cis women still hold traditional views on dating despite so many decades of activism. The women in your classes were likely expecting you to hit on them rather than the other way around. You may have overlooked signs of interest or flirting due to a poor ability to read social cues. Not many hetero cis women will walk up to a man and say bluntly, "I think you're hot, let's go do something together." YOU ARE NOT A FAILURE.