Personally, there are a few fantasy settings I like that have guns, like Warcraft, FF and the Lightbringer series. I wouldn't call Warhammer fantasy. The things with these is that you can remove the guns and nothing changes. Guns add nothing to the setting or the plot in fantasy, save a bit of variety.
And a bit of variety is good, no?
Reputable in terms of popularity? Perhaps? Not a fan of Blizzard personally and I think WoW is a terrible MMO compared to those that came before it. Also, Orcs are aliens from another planet? What's up with that? Final Fantasy, in general, is a terrible franchise that has been in decline steadily since FFVII. I also wouldn't use JRPGs as the shining example of fantasy with guns, as they have largely fallen out of favor compared to their western counterpart.
This is certainly a highly-debatable and subjective topic. When I think of great fantasy games, I immediately gravitate towards The Elder Scrolls, The Witcher, LOTR (even if the games have historically been bad), etc.
The claim was made that guns "ruin" a fantasy setting.
None of the settings mentioneded can be considered "ruined" with their contuining popularity and being almost a house-hold name when asked for an example of the setting. Opinions on them may vary, but they are still popular and continuing settings.
Also minor nitpick, guns have been in warcraft since the RTS days of warcraft 2, warcraft 3 if you count personal ones. Guns and fantasy are not incompatible. The problem is, if you want a scenario where melee weapons are still widely used you'll have to limit firearms technology to flintlock pistols and muskets, which are basically useless in what you might call "adventuring combat". Add anything more powerful, and the question "Why the hell do people still use swords" doesn't have a convincing answer. Ship cannon are much less of a problem since they replace nothing that usually identifies a fantasy scenario, and they are technologically much simpler than personal firearms so that having them doesn't result in a technological inconsistency.
Anyway, adding personal firearms to the DA world would have very limited benefits compared to the problems it would cause, lore-wise and from a gameplay perspective, so it's best to leave them out of the picture.
Nonsense. Video games have the lovely advantage of not being limited to reality (that's how we can survive being stabbed a dozen times while on fire and keep using our bows with our infite arrows after all), so firearms could use a different variant of the bow mechanics to function just fine.
And given that firearms already exist in the lore, that shouldn't be an issue either.