Well of course, since FS combat was modeled after WW2 planes and therefore extremely simplified and unrealistic. The goal was to have fighters going around absolute behemoths of capships acting as interactive background more or less. This would also explain the huge discrepancies between ship type sizes, for example Fenris being extremely small compared to an Orion, with nothing in between. Or stupidly slow speeds of these capships.
If you wanted to be realistic, you would need to adapt a fully newtonian flight model and that... would be not fun. You would need to actively cancel out your speed literally everywhere, for example during every turn, and it would be yet another layer of complexity over an already hard to pick up due to control complexity game.
This is generally what people call "rule of cool": it isn't realistic, often doesn't make sense at all, but is fun and simplifies gameplay considerably.
That said, I don't think making ships in Freespace faster in general is a bad idea, as long as the rest of the gameplay is tweaked to match this. At this point I'm winding down after playing Solaris a lot, and I'd say that this TC is a very good example to follow in this case. Ships are a couple times faster in general, including capital ships, which also gives a bunch of maneuver space for the mod developer to make speed differences between ships larger and much more meaningful. And the mod definitely takes advantage of this, as capital ships are actually maneuvering there, differences between fighter speeds are larger and mean quite a bit in the battlefield. To match this, Solaris has faster moving weapons, a very important feature of minor aim assist (at these distances and speeds trying to hit tiny fighters is not fun) and a bunch of additional useful movement options for the player (glide, strafe).