As of now, you can fire a gun one less time than the size of the clip, wait a short period of time, and repeat. Another method (more popular with 2-shot guns, like Alchemers) is to fire - switch - fire - etc These techniques allows guns to skip reloading entirely. This is different from swords, because if you shield cancel an FF's first hit 3 times in rapid succession, it will not allow you to do it again for a minute period of time. I have long disliked that guns are capable of this, and a long time ago came up with this idea.
What I propose is a way to make reloading unavoidable, while still letting guns retain their great usefulness. What I think should be done to achieve this is to make the clips a good bit larger (maybe x2 or x2.5), but make it keep track of the shots fired (perhaps have a little graphic that displays the number of rounds in the clip and greys them out as you fire them (can be toggled)) so that once you run out of rounds, you are forced to reload. This would, for example, let you fire an Alchemer 4 times, before being forced to reload. I think that this would allow Polarises to retain their popular PvP usage, but would make you vulnerable for a short period every so many shots.
In PvE, I think "Ammo" should be a drop from mobs and could refill all of your guns' clips by one. There could be a less-common drop that entirely refills all of guns' clips.
I that this would alleviate some of the disdain people have for guns, while still allowing guns to be quite good.
You do know you can do the exact same thing with swords right? I used to use duel Sealed Swords in Tier 2 Lockdown for this very reason, and my main loadout for there right now is Rigadoon + Flamberge, which I switch-hit with.
The wait time on swords is basically a guns reload. You can also wait just a tad bit with swords to reset the combo just as well as you can with guns.
It's also worth a mention that switch-shooting requires at least two weapons for the most part, which takes up a weapon slot in order to use. Not everyone has two alchemers, and the ones that do may not want to sacrifice a weapon slot just to switch-shoot with them unless they mained as a gunner.
What you're proposing is a fix to something that isn't broken.