I have never had an aversion to guns in fantasy, but I have had an aversion to guns in D&D. Its nothing on a pure mechanical basis - you can make it work. But it just never fit for me perception-wise. I cut my teeth on 1e - there, your mid-level fighter could stroll through an open field just ignoring arrow fire -- even if they did hit my great AC (based on Dex and Armor), that piddly 3hp of damage really was not going to stop my guy from taking is normal action. Archers are what you killed last cuz they were not a "threat".
Now, that is just a trope of the system. Even under 3e and 4e, you need an archer "build" in order to be dangerous. A commoner picking up a bow is back to 1e in my mindset ("fire your bow, then I will run my sword through you heart or incinerate you with magic!"). But since I am not sitting there watching a ton of war movies based on the bow and arrow period, it just faded into the gamest background like many other things.
Guns are a different matter. While the early guns a varying degrees of effectiveness, that is not what pops into my mind when the word "gun" is used. When guns are fired, you get to cover. That what happens in the cowboy movies, in the war movies, and in Dirty Harry. But in D&D, what is not what happens. It is just a funny crossbow mechanically (yawn).
(and thats why I love Savage Worlds - when guns or even bows come into play, you best head to Cover, partner! - I would to play in a Solomon Kane setting - guns and swords!).
That is one trope I wish would die a slow painful death.
I played 1E to and I hated that. Being shot with arrows should be scary. There was a reason armies charged as fast as possible to get to the other side they wanted to get our of range of the long bows. Those bows could devastate an army.