Ultimately, fixed-gear is a fad. You can list advantages and try to justify why everyone should ride one. But when the same exact thing has been around a hundred years, has been abandoned by 99.9999% of the cyclists in the world, and is then introduced as the greatest thing since sliced bread, that's a pretty good clue that it is trendiness at work, not superiority. Banana seats came and banana seats went. "Tank" frames came and they went. Wait 30 years, and fixed-gear bikes will be selling for $5 at garage sales, while some other wonderbike is the latest in-thing.