I don’t even think it’s the tyranny of the majority. It’s more of the tyranny of the vocal population.
Just look at the dps role, besides genji, most popular heroes are actually ranged/hitscans (Cassidy, Widow, Hanzo, Soldier and Ashe). Even genji, his popularity is probably more of his character design as being a cyber ninja instead of being “dive”. Or you see wrecking ball players are extremely vocal online, yet it’s one of the least popular hero. Or in OW1, I remeber hog/zarya had much higher pick rate than any of those dive tanks for a long time.
I genuinely think the people who main dive heroes are lot more vocal, and ofc they are going to claim their heores are the most fun/fair ones.