Why do most people want to play as a non roman faction?

[Thoros of Myr]

Becuase the fun is beating Rome, not playing them :)

[Tamur]

I'm playing as Julii, and will happily do so for a while yet to learn the game mechanics and what works/what doesn't diplomatically.

But once I get comfortable with the game, I want to smash the Julii as punishment for their leader's crimes. The genocides against the Helvetii and Venetians are inexcuseable, and my Gaelic blood boils every time I read about it.

No satisfaction will be greater than playing the Gauls and springing a nice little winter surprise on Julius.