FS3 is designed around the concept that you should be able to make a skilled veteran right out of the gate. Now it's configurable so not all games use it that way, but that idea was central to its design. Many of the Battlestar games have used it along with a hodgepodge of other MUs (Game of Bones, 100, Wing Commander, at least one Star Wars game, etc.).
Because you can start high, XP is intended to be superfluous, and the slow advancement pisses some people off. Also some folks don't like it because not everyone starts out "even" in terms of their power level. But both of those things are by design, so c'est la vie. Can't please everyone.