They weren't even that charming. Just a little more able to keep their mouths shut while in front of mixed company.
Source: In the early 2000s, I worked in a position that was two degrees away from BillG. I put together presentations and demos that my boss delivered to the man.
Listen to how Melinda talks about her relationship with him for clues about how little actual charisma he has. She's responsible for every bit of humanity he's shown over the last three decades. There were interviews he gave prior to marrying her where he expressed open disdain toward humanitarian endeavors.