That's not a fact, that's a biased personal assessment, based on what I cannot guess.
Gimbals and turrets have benefits that anyone, even someone with utterly flawless aim, can leverage to their advantage. Pretending that these advantages don't exist, don't matter, or that those that leverage them also means they cannot aim, is flatly ignorant. Non-fixed mounts on at least some weapons are mandatory if you want weapons with very different projectile velocities to converge. Being able to fire a significant deviation from where the ship is pointing is an enormous asset when it comes to delivering damage while staying evasive. Different mounts also change other weapon properties which can be an asset in and of themselves....for example, I like emissive, corrosive, and dispersal turrets because the lower RoF of turrets extends their endurance, and these effects are completely independent of damage (and I do not use turrets to deal damage, I have fixed weapons for that).
Anyway, I always recommend starting with fixed weapons (and think the switch from fixed lasers to gimbals as the default on the starting Sidewinder has done a huge disservice to players), then after they've been mastered, transitioning to auto-aiming ones, where they are appropriate, so that they aren't being used as an aiming crutch. However, limiting one's self to only fixed weapons, when something else would provide a tangible advantage, doesn't make one a better pilot or more likely to win; it's just a preference and an irrational one at that.
In the end, my CMDR fights to survive or to win, not to demonstrate his skills. As a player, other's assessments of my abilities, beyond those criticisms I can use to improve my play, are neither here nor there.