If they slapped the word "Dwemer" on it, then maybe I'd accept one or two steam-powered guns in a game (don't ask me how that would work, though). Please note that I'm not suggesting that technology should advance to gunpowder level, but rather that we should find ancient artifacts from the only society we know of so far that might have had the gumption to make such a strange and wonderful thing. I am also definitely not suggesting that we bring the Dwemer back.
Overall, though, technology advances when the need for it arises. We have magicka; personal firearms aren't a necessity in this world. Great cannons aren't as important because the Empire (in its many incarnations) has always fielded enough people in the Legions to make up for any lack of technology, and any time the Empire wasn't in charge, the factions that remained were never powerful or rich enough to develop that kind of weaponry. With the rise of the Thalmor, this status quo is changing somewhat, but I would have to guess that the coming Great War will bring about the end of this multi-state conflict before the R&D folks can figure out how to make any gunpowder weapon work. And again, if the R&D folks are looking into superweapons, I'm pretty certain the first place they'd look would be magicka and magicka-related artifacts; unless someone somehow blots out the sun (perhaps a legacy of Dawnguard), there would be no reason for developers to look into more mundane weapons of power.
And as the people above have said, why would you want guns anyway? "magick is kinda dumb anyway" is not a reason, especially since I think guns in this setting are even more so.