That's what you, the captain, likes because that's what's effective. As for the gunner himself, staying in one place isn't all that fun, you spend a lot of time out of arc and twiddling your thumbs. If running around became mechanically advantageous, as it quite possibly would if ammo loading wasn't such a huge constraint, then the gunner could have his fun and you wouldn't WANT him to not have his fun. It's the same thing as the issue with gungineers, we captains don't ask people to not play gunner because we don't think playing a gunner isn't fun (it is), but because we're put at a mechanical disadvantage by having one or two. Whenever possible the fun way of doing things should be the competitive way of doing things.
I REALLY don't want to stick with the status quo just because that's how things are right now, I want to see some specific and nontrivial example of why keeping things the way they are now is worth not having more intuitive mechanics (currently I find myself explaining how ammo loading works A LOT when it should work as it appears, the guns animate like they're self-loading) and more freedom of movement for the gunner (and more opportunities for tactical ammo switching which is grossly underused).
Even IF the gungineer becomes a bit more useful from being able to leave their gun alone a bit longer (which I doubt would have a major impact as gungineers are only really capable of manning one specific gun and will have to stay on it anyways just to keep up DPS, the ammo loading is more of a convenience during downtime compared to the gunner's in-combat advantage), I say it's still worth the mechanics matching the animations and just making more sense. The way it is right now just makes the game more complex without making it much deeper (if at all).
Was this tried before and removed for some specfici reason? Has Muse commented on it and given this or that reason for not changing their minds about it? What is Muse's stated reason for the current mechanic? How long ago was that made, and does it still apply to the current meta?